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2019-09-24mm/memory_hotplug.c: use PFN_UP / PFN_DOWN in walk_system_ram_range()Gravatar David Hildenbrand 1-2/+2
Patch series "mm/memory_hotplug: online_pages() cleanups", v2. Some cleanups (+ one fix for a special case) in the context of online_pages(). This patch (of 5): This makes it clearer that we will never call func() with duplicate PFNs in case we have multiple sub-page memory resources. All unaligned parts of PFNs are completely discarded. Link: http://lkml.kernel.org/r/20190814154109.3448-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Wei Yang <richardw.yang@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Nadav Amit <namit@vmware.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Arun KS <arunks@codeaurora.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/memory_hotplug.c: prevent memory leak when reusing pgdatGravatar Wei Yang 1-1/+9
When offlining a node in try_offline_node(), pgdat is not released. So that pgdat could be reused in hotadd_new_pgdat(). While we reallocate pgdat->per_cpu_nodestats if this pgdat is reused. This patch prevents the memory leak by just allocating per_cpu_nodestats when it is a new pgdat. Link: http://lkml.kernel.org/r/20190813020608.10194-1-richardw.yang@linux.intel.com Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <OSalvador@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24drivers/base/memory.c: don't store end_section_nr in memory blocksGravatar David Hildenbrand 4-8/+6
Each memory block spans the same amount of sections/pages/bytes. The size is determined before the first memory block is created. No need to store what we can easily calculate - and the calculations even look simpler now. Michal brought up the idea of variable-sized memory blocks. However, if we ever implement something like this, we will need an API compatibility switch and reworks at various places (most code assumes a fixed memory block size). So let's cleanup what we have right now. While at it, fix the variable naming in register_mem_sect_under_node() - we no longer talk about a single section. Link: http://lkml.kernel.org/r/20190809110200.2746-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24driver/base/memory.c: validate memory block size earlyGravatar David Hildenbrand 2-25/+12
Let's validate the memory block size early, when initializing the memory device infrastructure. Fail hard in case the value is not suitable. As nobody checks the return value of memory_dev_init(), turn it into a void function and fail with a panic in all scenarios instead. Otherwise, we'll crash later during boot when core/drivers expect that the memory device infrastructure (including memory_block_size_bytes()) works as expected. I think long term, we should move the whole memory block size configuration (set_memory_block_size_order() and memory_block_size_bytes()) into drivers/base/memory.c. Link: http://lkml.kernel.org/r/20190806090142.22709-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24drivers/base/memory.c: fixup documentation of ↵Gravatar David Hildenbrand 1-5/+6
removable/phys_index/block_size_bytes Let's rephrase to memory block terminology and add some further clarifications. Link: http://lkml.kernel.org/r/20190806080826.5963-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24drivers/base/node.c: simplify unregister_memory_block_under_nodes()Gravatar David Hildenbrand 2-24/+16
We don't allow to offline memory block devices that belong to multiple numa nodes. Therefore, such devices can never get removed. It is sufficient to process a single node when removing the memory block. No need to iterate over each and every PFN. We already have the nid stored for each memory block. Make sure that the nid always has a sane value. Please note that checking for node_online(nid) is not required. If we would have a memory block belonging to a node that is no longer offline, then we would have a BUG in the node offlining code. Link: http://lkml.kernel.org/r/20190719135244.15242-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/memory_hotplug: remove move_pfn_range()Gravatar David Hildenbrand 1-16/+8
Let's remove this indirection. We need the zone in the caller either way, so let's just detect it there. Add some documentation for move_pfn_range_to_zone() instead. [akpm@linux-foundation.org: restore newline, per David] Link: http://lkml.kernel.org/r/20190724142324.3686-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: do not hash address in print_bad_pte()Gravatar Kefeng Wang 1-1/+1
Using %px to show the actual address in print_bad_pte() to help us to debug issue. Link: http://lkml.kernel.org/r/20190831011816.141002-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: consolidate pgtable_cache_init() and pgd_cache_init()Gravatar Mike Rapoport 36-130/+5
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem cache for page table allocations on several architectures that do not use PAGE_SIZE tables for one or more levels of the page table hierarchy. Most architectures do not implement these functions and use __weak default NOP implementation of pgd_cache_init(). Since there is no such default for pgtable_cache_init(), its empty stub is duplicated among most architectures. Rename the definitions of pgd_cache_init() to pgtable_cache_init() and drop empty stubs of pgtable_cache_init(). Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Will Deacon <will@kernel.org> [arm64] Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24microblaze: switch to generic version of pte allocationGravatar Mike Rapoport 1-36/+3
The microblaze implementation of pte_alloc_one() has a provision to allocated PTEs from high memory, but neither CONFIG_HIGHPTE nor pte_map*() versions for suitable for HIGHPTE are defined. Except that, microblaze version of pte_alloc_one() is identical to the generic one as well as the implementations of pte_free() and pte_free_kernel(). Switch microblaze to use the generic versions of these functions. Also remove pte_free_slow() that is not referenced anywhere in the code. Link: http://lkml.kernel.org/r/1565690952-32158-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Michal Simek <monstr@monstr.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24sh: switch to generic version of pte allocationGravatar Mike Rapoport 1-33/+1
The sh implementation pte_alloc_one(), pte_alloc_one_kernel(), pte_free_kernel() and pte_free() is identical to the generic except of lack of __GFP_ACCOUNT for the user PTEs allocation. Switch sh to use generic version of these functions. Link: http://lkml.kernel.org/r/1565250728-21721-4-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24ia64: switch to generic version of pte allocationGravatar Mike Rapoport 1-30/+2
The ia64 implementation pte_alloc_one(), pte_alloc_one_kernel(), pte_free_kernel() and pte_free() is identical to the generic except of lack of __GFP_ACCOUNT for the user PTEs allocation. Switch ia64 to use generic version of these functions. Link: http://lkml.kernel.org/r/1565250728-21721-3-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: remove quicklist page table cachesGravatar Nicholas Piggin 39-395/+25
Patch series "mm: remove quicklist page table caches". A while ago Nicholas proposed to remove quicklist page table caches [1]. I've rebased his patch on the curren upstream and switched ia64 and sh to use generic versions of PTE allocation. [1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com This patch (of 3): Remove page table allocator "quicklists". These have been around for a long time, but have not got much traction in the last decade and are only used on ia64 and sh architectures. The numbers in the initial commit look interesting but probably don't apply anymore. If anybody wants to resurrect this it's in the git history, but it's unhelpful to have this code and divergent allocator behaviour for minor archs. Also it might be better to instead make more general improvements to page allocator if this is still so slow. Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: release the spinlock on zap_pte_rangeGravatar Minchan Kim 1-2/+8
In our testing (camera recording), Miguel and Wei found unmap_page_range() takes above 6ms with preemption disabled easily. When I see that, the reason is it holds page table spinlock during entire 512 page operation in a PMD. 6.2ms is never trivial for user experince if RT task couldn't run in the time because it could make frame drop or glitch audio problem. I had a time to benchmark it via adding some trace_printk hooks between pte_offset_map_lock and pte_unmap_unlock in zap_pte_range. The testing device is 2018 premium mobile device. I can get 2ms delay rather easily to release 2M(ie, 512 pages) when the task runs on little core even though it doesn't have any IPI and LRU lock contention. It's already too heavy. If I remove activate_page, 35-40% overhead of zap_pte_range is gone so most of overhead(about 0.7ms) comes from activate_page via mark_page_accessed. Thus, if there are LRU contention, that 0.7ms could accumulate up to several ms. So this patch adds a check for need_resched() in the loop, and a preemption point if necessary. Link: http://lkml.kernel.org/r/20190731061440.GC155569@google.com Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Miguel de Dios <migueldedios@google.com> Reported-by: Wei Wang <wvw@google.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: remove redundant assignment of entryGravatar Wei Yang 1-1/+0
Since ptent will not be changed after previous assignment of entry, it is not necessary to do the assignment again. Link: http://lkml.kernel.org/r/20190708082740.21111-1-richardw.yang@linux.intel.com Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24net/xdp: convert put_page() to put_user_page*()Gravatar John Hubbard 1-8/+1
For pages that were retained via get_user_pages*(), release those pages via the new put_user_page*() routines, instead of via put_page() or release_pages(). This is part a tree-wide conversion, as described in fc1d8e7cca2d ("mm: introduce put_user_page*(), placeholder versions"). Link: http://lkml.kernel.org/r/20190724044537.10458-4-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24drivers/gpu/drm/via: convert put_page() to put_user_page*()Gravatar John Hubbard 1-8/+2
For pages that were retained via get_user_pages*(), release those pages via the new put_user_page*() routines, instead of via put_page() or release_pages(). This is part a tree-wide conversion, as described in fc1d8e7cca2d ("mm: introduce put_user_page*(), placeholder versions"). Also reverse the order of a comparison, in order to placate checkpatch.pl. Link: http://lkml.kernel.org/r/20190724044537.10458-3-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/gup: add make_dirty arg to put_user_pages_dirty_lock()Gravatar akpm@linux-foundation.org 7-92/+58
[11~From: John Hubbard <jhubbard@nvidia.com> Subject: mm/gup: add make_dirty arg to put_user_pages_dirty_lock() Patch series "mm/gup: add make_dirty arg to put_user_pages_dirty_lock()", v3. There are about 50+ patches in my tree [2], and I'll be sending out the remaining ones in a few more groups: * The block/bio related changes (Jerome mostly wrote those, but I've had to move stuff around extensively, and add a little code) * mm/ changes * other subsystem patches * an RFC that shows the current state of the tracking patch set. That can only be applied after all call sites are converted, but it's good to get an early look at it. This is part a tree-wide conversion, as described in fc1d8e7cca2d ("mm: introduce put_user_page*(), placeholder versions"). This patch (of 3): Provide more capable variation of put_user_pages_dirty_lock(), and delete put_user_pages_dirty(). This is based on the following: 1. Lots of call sites become simpler if a bool is passed into put_user_page*(), instead of making the call site choose which put_user_page*() variant to call. 2. Christoph Hellwig's observation that set_page_dirty_lock() is usually correct, and set_page_dirty() is usually a bug, or at least questionable, within a put_user_page*() calling chain. This leads to the following API choices: * put_user_pages_dirty_lock(page, npages, make_dirty) * There is no put_user_pages_dirty(). You have to hand code that, in the rare case that it's required. [jhubbard@nvidia.com: remove unused variable in siw_free_plist()] Link: http://lkml.kernel.org/r/20190729074306.10368-1-jhubbard@nvidia.com Link: http://lkml.kernel.org/r/20190724044537.10458-2-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: vmscan: do not share cgroup iteration between reclaimersGravatar Johannes Weiner 1-20/+2
One of our services observed a high rate of cgroup OOM kills in the presence of large amounts of clean cache. Debugging showed that the culprit is the shared cgroup iteration in page reclaim. Under high allocation concurrency, multiple threads enter reclaim at the same time. Fearing overreclaim when we first switched from the single global LRU to cgrouped LRU lists, we introduced a shared iteration state for reclaim invocations - whether 1 or 20 reclaimers are active concurrently, we only walk the cgroup tree once: the 1st reclaimer reclaims the first cgroup, the second the second one etc. With more reclaimers than cgroups, we start another walk from the top. This sounded reasonable at the time, but the problem is that reclaim concurrency doesn't scale with allocation concurrency. As reclaim concurrency increases, the amount of memory individual reclaimers get to scan gets smaller and smaller. Individual reclaimers may only see one cgroup per cycle, and that may not have much reclaimable memory. We see individual reclaimers declare OOM when there is plenty of reclaimable memory available in cgroups they didn't visit. This patch does away with the shared iterator, and every reclaimer is allowed to scan the full cgroup tree and see all of reclaimable memory, just like it would on a non-cgrouped system. This way, when OOM is declared, we know that the reclaimer actually had a chance. To still maintain fairness in reclaim pressure, disallow cgroup reclaim from bailing out of the tree walk early. Kswapd and regular direct reclaim already don't bail, so it's not clear why limit reclaim would have to, especially since it only walks subtrees to begin with. This change completely eliminates the OOM kills on our service, while showing no signs of overreclaim - no increased scan rates, %sys time, or abrupt free memory spikes. I tested across 100 machines that have 64G of RAM and host about 300 cgroups each. [ It's possible overreclaim never was a *practical* issue to begin with - it was simply a concern we had on the mailing lists at the time, with no real data to back it up. But we have also added more bail-out conditions deeper inside reclaim (e.g. the proportional exit in shrink_node_memcg) since. Regardless, now we have data that suggests full walks are more reliable and scale just fine. ] Link: http://lkml.kernel.org/r/20190812192316.13615-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: memcontrol: switch to rcu protection in drain_all_stock()Gravatar Roman Gushchin 1-8/+9
Commit 72f0184c8a00 ("mm, memcg: remove hotplug locking from try_charge") introduced css_tryget()/css_put() calls in drain_all_stock(), which are supposed to protect the target memory cgroup from being released during the mem_cgroup_is_descendant() call. However, it's not completely safe. In theory, memcg can go away between reading stock->cached pointer and calling css_tryget(). This can happen if drain_all_stock() races with drain_local_stock() performed on the remote cpu as a result of a work, scheduled by the previous invocation of drain_all_stock(). The race is a bit theoretical and there are few chances to trigger it, but the current code looks a bit confusing, so it makes sense to fix it anyway. The code looks like as if css_tryget() and css_put() are used to protect stocks drainage. It's not necessary because stocked pages are holding references to the cached cgroup. And it obviously won't work for works, scheduled on other cpus. So, let's read the stock->cached pointer and evaluate the memory cgroup inside a rcu read section, and get rid of css_tryget()/css_put() calls. Link: http://lkml.kernel.org/r/20190802192241.3253165-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, memcg: throttle allocators when failing reclaim over memory.highGravatar Chris Down 1-1/+125
We're trying to use memory.high to limit workloads, but have found that containment can frequently fail completely and cause OOM situations outside of the cgroup. This happens especially with swap space -- either when none is configured, or swap is full. These failures often also don't have enough warning to allow one to react, whether for a human or for a daemon monitoring PSI. Here is output from a simple program showing how long it takes in usec (column 2) to allocate a megabyte of anonymous memory (column 1) when a cgroup is already beyond its memory high setting, and no swap is available: [root@ktst ~]# systemd-run -p MemoryHigh=100M -p MemorySwapMax=1 \ > --wait -t timeout 300 /root/mdf [...] 95 1035 96 1038 97 1000 98 1036 99 1048 100 1590 101 1968 102 1776 103 1863 104 1757 105 1921 106 1893 107 1760 108 1748 109 1843 110 1716 111 1924 112 1776 113 1831 114 1766 115 1836 116 1588 117 1912 118 1802 119 1857 120 1731 [...] [System OOM in 2-3 seconds] The delay does go up extremely marginally past the 100MB memory.high threshold, as now we spend time scanning before returning to usermode, but it's nowhere near enough to contain growth. It also doesn't get worse the more pages you have, since it only considers nr_pages. The current situation goes against both the expectations of users of memory.high, and our intentions as cgroup v2 developers. In cgroup-v2.txt, we claim that we will throttle and only under "extreme conditions" will memory.high protection be breached. Likewise, cgroup v2 users generally also expect that memory.high should throttle workloads as they exceed their high threshold. However, as seen above, this isn't always how it works in practice -- even on banal setups like those with no swap, or where swap has become exhausted, we can end up with memory.high being breached and us having no weapons left in our arsenal to combat runaway growth with, since reclaim is futile. It's also hard for system monitoring software or users to tell how bad the situation is, as "high" events for the memcg may in some cases be benign, and in others be catastrophic. The current status quo is that we fail containment in a way that doesn't provide any advance warning that things are about to go horribly wrong (for example, we are about to invoke the kernel OOM killer). This patch introduces explicit throttling when reclaim is failing to keep memcg size contained at the memory.high setting. It does so by applying an exponential delay curve derived from the memcg's overage compared to memory.high. In the normal case where the memcg is either below or only marginally over its memory.high setting, no throttling will be performed. This composes well with system health monitoring and remediation, as these allocator delays are factored into PSI's memory pressure calculations. This both creates a mechanism system administrators or applications consuming the PSI interface to trivially see that the memcg in question is struggling and use that to make more reasonable decisions, and permits them enough time to act. Either of these can act with significantly more nuance than that we can provide using the system OOM killer. This is a similar idea to memory.oom_control in cgroup v1 which would put the cgroup to sleep if the threshold was violated, but it's also significantly improved as it results in visible memory pressure, and also doesn't schedule indefinitely, which previously made tracing and other introspection difficult (ie. it's clamped at 2*HZ per allocation through MEMCG_MAX_HIGH_DELAY_JIFFIES). Contrast the previous results with a kernel with this patch: [root@ktst ~]# systemd-run -p MemoryHigh=100M -p MemorySwapMax=1 \ > --wait -t timeout 300 /root/mdf [...] 95 1002 96 1000 97 1002 98 1003 99 1000 100 1043 101 84724 102 330628 103 610511 104 1016265 105 1503969 106 2391692 107 2872061 108 3248003 109 4791904 110 5759832 111 6912509 112 8127818 113 9472203 114 12287622 115 12480079 116 14144008 117 15808029 118 16384500 119 16383242 120 16384979 [...] As you can see, in the normal case, memory allocation takes around 1000 usec. However, as we exceed our memory.high, things start to increase exponentially, but fairly leniently at first. Our first megabyte over memory.high takes us 0.16 seconds, then the next is 0.46 seconds, then the next is almost an entire second. This gets worse until we reach our eventual 2*HZ clamp per batch, resulting in 16 seconds per megabyte. However, this is still making forward progress, so permits tracing or further analysis with programs like GDB. We use an exponential curve for our delay penalty for a few reasons: 1. We run mem_cgroup_handle_over_high to potentially do reclaim after we've already performed allocations, which means that temporarily going over memory.high by a small amount may be perfectly legitimate, even for compliant workloads. We don't want to unduly penalise such cases. 2. An exponential curve (as opposed to a static or linear delay) allows ramping up memory pressure stats more gradually, which can be useful to work out that you have set memory.high too low, without destroying application performance entirely. This patch expands on earlier work by Johannes Weiner. Thanks! [akpm@linux-foundation.org: fix max() warning] [akpm@linux-foundation.org: fix __udivdi3 ref on 32-bit] [akpm@linux-foundation.org: fix it even more] [chris@chrisdown.name: fix 64-bit divide even more] Link: http://lkml.kernel.org/r/20190723180700.GA29459@chrisdown.name Signed-off-by: Chris Down <chris@chrisdown.name> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: page cache: store only head pages in i_pagesGravatar Matthew Wilcox (Oracle) 8-96/+95
Transparent Huge Pages are currently stored in i_pages as pointers to consecutive subpages. This patch changes that to storing consecutive pointers to the head page in preparation for storing huge pages more efficiently in i_pages. Large parts of this are "inspired" by Kirill's patch https://lore.kernel.org/lkml/20170126115819.58875-2-kirill.shutemov@linux.intel.com/ Kirill and Huang Ying contributed several fixes. [willy@infradead.org: use compound_nr, squish uninit-var warning] Link: http://lkml.kernel.org/r/20190731210400.7419-1-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Jan Kara <jack@suse.cz> Reviewed-by: Kirill Shutemov <kirill@shutemov.name> Reviewed-by: Song Liu <songliubraving@fb.com> Tested-by: Song Liu <songliubraving@fb.com> Tested-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Tested-by: Qian Cai <cai@lca.pw> Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Song Liu <songliubraving@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/filemap.c: rewrite mapping_needs_writeback in less fancy mannerGravatar Konstantin Khlebnikov 1-2/+5
This actually checks that writeback is needed or in progress. Link: http://lkml.kernel.org/r/156378817069.1087.1302816672037672488.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/filemap.c: don't initiate writeback if mapping has no dirty pagesGravatar Konstantin Khlebnikov 1-1/+2
Functions like filemap_write_and_wait_range() should do nothing if inode has no dirty pages or pages currently under writeback. But they anyway construct struct writeback_control and this does some atomic operations if CONFIG_CGROUP_WRITEBACK=y - on fast path it locks inode->i_lock and updates state of writeback ownership, on slow path might be more work. Current this path is safely avoided only when inode mapping has no pages. For example generic_file_read_iter() calls filemap_write_and_wait_range() at each O_DIRECT read - pretty hot path. This patch skips starting new writeback if mapping has no dirty tags set. If writeback is already in progress filemap_write_and_wait_range() will wait for it. Link: http://lkml.kernel.org/r/156378816804.1087.8607636317907921438.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, page_owner, debug_pagealloc: save and dump freeing stack traceGravatar Vlastimil Babka 3-14/+45
The debug_pagealloc functionality is useful to catch buggy page allocator users that cause e.g. use after free or double free. When page inconsistency is detected, debugging is often simpler by knowing the call stack of process that last allocated and freed the page. When page_owner is also enabled, we record the allocation stack trace, but not freeing. This patch therefore adds recording of freeing process stack trace to page owner info, if both page_owner and debug_pagealloc are configured and enabled. With only page_owner enabled, this info is not useful for the memory leak debugging use case. dump_page() is adjusted to print the info. An example result of calling __free_pages() twice may look like this (note the page last free stack trace): BUG: Bad page state in process bash pfn:13d8f8 page:ffffc31984f63e00 refcount:-1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x1affff800000000() raw: 01affff800000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000000 page dumped because: nonzero _refcount page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL) prep_new_page+0x143/0x150 get_page_from_freelist+0x289/0x380 __alloc_pages_nodemask+0x13c/0x2d0 khugepaged+0x6e/0xc10 kthread+0xf9/0x130 ret_from_fork+0x3a/0x50 page last free stack trace: free_pcp_prepare+0x134/0x1e0 free_unref_page+0x18/0x90 khugepaged+0x7b/0xc10 kthread+0xf9/0x130 ret_from_fork+0x3a/0x50 Modules linked in: CPU: 3 PID: 271 Comm: bash Not tainted 5.3.0-rc4-2.g07a1a73-default+ #57 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x85/0xc0 bad_page.cold+0xba/0xbf rmqueue_pcplist.isra.0+0x6c5/0x6d0 rmqueue+0x2d/0x810 get_page_from_freelist+0x191/0x380 __alloc_pages_nodemask+0x13c/0x2d0 __get_free_pages+0xd/0x30 __pud_alloc+0x2c/0x110 copy_page_range+0x4f9/0x630 dup_mmap+0x362/0x480 dup_mm+0x68/0x110 copy_process+0x19e1/0x1b40 _do_fork+0x73/0x310 __x64_sys_clone+0x75/0x80 do_syscall_64+0x6e/0x1e0 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f10af854a10 ... Link: http://lkml.kernel.org/r/20190820131828.22684-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, page_owner: keep owner info when freeing the pageGravatar Vlastimil Babka 2-10/+25
For debugging purposes it might be useful to keep the owner info even after page has been freed, and include it in e.g. dump_page() when detecting a bad page state. For that, change the PAGE_EXT_OWNER flag meaning to "page owner info has been set at least once" and add new PAGE_EXT_OWNER_ACTIVE for tracking whether page is supposed to be currently tracked allocated or free. Adjust dump_page() accordingly, distinguishing free and allocated pages. In the page_owner debugfs file, keep printing only allocated pages so that existing scripts are not confused, and also because free pages are irrelevant for the memory statistics or leak detection that's the typical use case of the file, anyway. Link: http://lkml.kernel.org/r/20190820131828.22684-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, page_owner: record page owner for each subpageGravatar Vlastimil Babka 1-12/+28
Patch series "debug_pagealloc improvements through page_owner", v2. The debug_pagealloc functionality serves a similar purpose on the page allocator level that slub_debug does on the kmalloc level, which is to detect bad users. One notable feature that slub_debug has is storing stack traces of who last allocated and freed the object. On page level we track allocations via page_owner, but that info is discarded when freeing, and we don't track freeing at all. This series improves those aspects. With both debug_pagealloc and page_owner enabled, we can then get bug reports such as the example in Patch 4. SLUB debug tracking additionally stores cpu, pid and timestamp. This could be added later, if deemed useful enough to justify the additional page_ext structure size. This patch (of 3): Currently, page owner info is only recorded for the first page of a high-order allocation, and copied to tail pages in the event of a split page. With the plan to keep previous owner info after freeing the page, it would be benefical to record page owner for each subpage upon allocation. This increases the overhead for high orders, but that should be acceptable for a debugging option. The order stored for each subpage is the order of the whole allocation. This makes it possible to calculate the "head" pfn and to recognize "tail" pages (quoted because not all high-order allocations are compound pages with true head and tail pages). When reading the page_owner debugfs file, keep skipping the "tail" pages so that stats gathered by existing scripts don't get inflated. Link: http://lkml.kernel.org/r/20190820131828.22684-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: replace list_move_tail() with add_page_to_lru_list_tail()Gravatar Yu Zhao 1-8/+6
This is a cleanup patch that replaces two historical uses of list_move_tail() with relatively recent add_page_to_lru_list_tail(). Link: http://lkml.kernel.org/r/20190716212436.7137-1-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: introduce compound_nr()Gravatar Matthew Wilcox (Oracle) 18-25/+30
Replace 1 << compound_order(page) with compound_nr(page). Minor improvements in readability. Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: introduce page_shift()Gravatar Matthew Wilcox (Oracle) 3-9/+12
Replace PAGE_SHIFT + compound_order(page) with the new page_shift() function. Minor improvements in readability. [akpm@linux-foundation.org: fix build in tce_page_is_contained()] Link: http://lkml.kernel.org/r/201907241853.yNQTrJWd%25lkp@intel.com Link: http://lkml.kernel.org/r/20190721104612.19120-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: introduce page_size()Gravatar Matthew Wilcox (Oracle) 17-38/+35
Patch series "Make working with compound pages easier", v2. These three patches add three helpers and convert the appropriate places to use them. This patch (of 3): It's unnecessarily hard to find out the size of a potentially huge page. Replace 'PAGE_SIZE << compound_order(page)' with page_size(page). Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/rmap.c: remove set but not used variable 'cstart'Gravatar YueHaibing 1-3/+1
Fixes gcc '-Wunused-but-set-variable' warning: mm/rmap.c: In function page_mkclean_one: mm/rmap.c:906:17: warning: variable cstart set but not used [-Wunused-but-set-variable] It is not used any more since commit cdb07bdea28e ("mm/rmap.c: remove redundant variable cend") Link: http://lkml.kernel.org/r/20190724141453.38536-1-yuehaibing@huawei.com Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/page_poison.c: fix a typo in a commentGravatar Christophe JAILLET 1-1/+1
s/posioned/poisoned/ Link: http://lkml.kernel.org/r/20190721180908.6534-1-christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24lib/test_kasan.c: add roundtrip testsGravatar Mark Rutland 1-0/+41
In several places we need to be able to operate on pointers which have gone via a roundtrip: virt -> {phys,page} -> virt With KASAN_SW_TAGS, we can't preserve the tag for SLUB objects, and the {phys,page} -> virt conversion will use KASAN_TAG_KERNEL. This patch adds tests to ensure that this works as expected, without false positives which have recently been spotted [1,2] in testing. [1] https://lore.kernel.org/linux-arm-kernel/20190819114420.2535-1-walter-zh.wu@mediatek.com/ [2] https://lore.kernel.org/linux-arm-kernel/20190819132347.GB9927@lakrids.cambridge.arm.com/ [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20190821153927.28630-1-mark.rutland@arm.com Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24kasan: add memory corruption identification for software tag-based modeGravatar Walter Wu 5-13/+99
Add memory corruption identification at bug report for software tag-based mode. The report shows whether it is "use-after-free" or "out-of-bound" error instead of "invalid-access" error. This will make it easier for programmers to see the memory corruption problem. We extend the slab to store five old free pointer tag and free backtrace, we can check if the tagged address is in the slab record and make a good guess if the object is more like "use-after-free" or "out-of-bound". therefore every slab memory corruption can be identified whether it's "use-after-free" or "out-of-bound". [aryabinin@virtuozzo.com: simplify & clenup code] Link: https://lkml.kernel.org/r/3318f9d7-a760-3cc8-b700-f06108ae745f@virtuozzo.com] Link: http://lkml.kernel.org/r/20190821180332.11450-1-aryabinin@virtuozzo.com Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/kmemleak: increase the max mem pool to 1MGravatar Qian Cai 1-1/+1
There are some machines with slow disk and fast CPUs. When they are under memory pressure, it could take a long time to swap before the OOM kicks in to free up some memory. As the results, it needs a large mem pool for kmemleak or suffering from higher chance of a kmemleak metadata allocation failure. 524288 proves to be the good number for all architectures here. Increase the upper bound to 1M to leave some room for the future. Link: http://lkml.kernel.org/r/1565807572-26041-1-git-send-email-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/kmemleak.c: record the current memory pool sizeGravatar Qian Cai 1-1/+2
The only way to obtain the current memory pool size for a running kernel is to check the kernel config file which is inconvenient. Record it in the kernel messages. [akpm@linux-foundation.org: s/memory pool size/memory pool/available/, per Catalin] Link: http://lkml.kernel.org/r/1565809631-28933-1-git-send-email-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: kmemleak: use the memory pool for early allocationsGravatar Catalin Marinas 3-245/+33
Currently kmemleak uses a static early_log buffer to trace all memory allocation/freeing before the slab allocator is initialised. Such early log is replayed during kmemleak_init() to properly initialise the kmemleak metadata for objects allocated up that point. With a memory pool that does not rely on the slab allocator, it is possible to skip this early log entirely. In order to remove the early logging, consider kmemleak_enabled == 1 by default while the kmem_cache availability is checked directly on the object_cache and scan_area_cache variables. The RCU callback is only invoked after object_cache has been initialised as we wouldn't have any concurrent list traversal before this. In order to reduce the number of callbacks before kmemleak is fully initialised, move the kmemleak_init() call to mm_init(). [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: remove WARN_ON(), per Catalin] Link: http://lkml.kernel.org/r/20190812160642.52134-4-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: kmemleak: simple memory allocation pool for kmemleak objectsGravatar Catalin Marinas 1-2/+52
Add a memory pool for struct kmemleak_object in case the normal kmem_cache_alloc() fails under the gfp constraints passed by the caller. The mem_pool[] array size is currently fixed at 16000. We are not using the existing mempool kernel API since this requires the slab allocator to be available (for pool->elements allocation). A subsequent kmemleak patch will replace the static early log buffer with the pool allocation introduced here and this functionality is required to be available before the slab was initialised. Link: http://lkml.kernel.org/r/20190812160642.52134-3-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: kmemleak: make the tool tolerant to struct scan_area allocation failuresGravatar Catalin Marinas 1-6/+10
Patch series "mm: kmemleak: Use a memory pool for kmemleak object allocations", v3. Following the discussions on v2 of this patch(set) [1], this series takes slightly different approach: - it implements its own simple memory pool that does not rely on the slab allocator - drops the early log buffer logic entirely since it can now allocate metadata from the memory pool directly before kmemleak is fully initialised - CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE option is renamed to CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE - moves the kmemleak_init() call earlier (mm_init()) - to avoid a separate memory pool for struct scan_area, it makes the tool robust when such allocations fail as scan areas are rather an optimisation [1] http://lkml.kernel.org/r/20190727132334.9184-1-catalin.marinas@arm.com This patch (of 3): Object scan areas are an optimisation aimed to decrease the false positives and slightly improve the scanning time of large objects known to only have a few specific pointers. If a struct scan_area fails to allocate, kmemleak can still function normally by scanning the full object. Introduce an OBJECT_FULL_SCAN flag and mark objects as such when scan_area allocation fails. Link: http://lkml.kernel.org/r/20190812160642.52134-2-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16KGravatar Nicolas Boichat 1-1/+1
The current default value (400) is too low on many systems (e.g. some ARM64 platform takes up 1000+ entries). syzbot uses 16000 as default value, and has proved to be enough on beefy configurations, so let's pick that value. This consumes more RAM on boot (each entry is 160 bytes, so in total ~2.5MB of RAM), but the memory would later be freed (early_log is __initdata). Link: http://lkml.kernel.org/r/20190730154027.101525-1-drinkcat@chromium.org Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Suggested-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Kees Cook <keescook@chromium.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm/slub.c: fix -Wunused-function compiler warningsGravatar Qian Cai 1-0/+2
tid_to_cpu() and tid_to_event() are only used in note_cmpxchg_failure() when SLUB_DEBUG_CMPXCHG=y, so when SLUB_DEBUG_CMPXCHG=n by default, Clang will complain that those unused functions. Link: http://lkml.kernel.org/r/1568752232-5094-1-git-send-email-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, slab: move memcg_cache_params structure to mm/slab.hGravatar Waiman Long 2-62/+63
The memcg_cache_params structure is only embedded into the kmem_cache of slab and slub allocators as defined in slab_def.h and slub_def.h and used internally by mm code. There is no needed to expose it in a public header. So move it from include/linux/slab.h to mm/slab.h. It is just a refactoring patch with no code change. In fact both the slub_def.h and slab_def.h should be moved into the mm directory as well, but that will probably cause many merge conflicts. Link: http://lkml.kernel.org/r/20190718180827.18758-1-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, slab: extend slab/shrink to shrink all memcg cachesGravatar Waiman Long 4-5/+48
Currently, a value of '1" is written to /sys/kernel/slab/<slab>/shrink file to shrink the slab by flushing out all the per-cpu slabs and free slabs in partial lists. This can be useful to squeeze out a bit more memory under extreme condition as well as making the active object counts in /proc/slabinfo more accurate. This usually applies only to the root caches, as the SLUB_MEMCG_SYSFS_ON option is usually not enabled and "slub_memcg_sysfs=1" not set. Even if memcg sysfs is turned on, it is too cumbersome and impractical to manage all those per-memcg sysfs files in a real production system. So there is no practical way to shrink memcg caches. Fix this by enabling a proper write to the shrink sysfs file of the root cache to scan all the available memcg caches and shrink them as well. For a non-root memcg cache (when SLUB_MEMCG_SYSFS_ON or slub_memcg_sysfs is on), only that cache will be shrunk when written. On a 2-socket 64-core 256-thread arm64 system with 64k page after a parallel kernel build, the the amount of memory occupied by slabs before shrinking slabs were: # grep task_struct /proc/slabinfo task_struct 53137 53192 4288 61 4 : tunables 0 0 0 : slabdata 872 872 0 # grep "^S[lRU]" /proc/meminfo Slab: 3936832 kB SReclaimable: 399104 kB SUnreclaim: 3537728 kB After shrinking slabs (by echoing "1" to all shrink files): # grep "^S[lRU]" /proc/meminfo Slab: 1356288 kB SReclaimable: 263296 kB SUnreclaim: 1092992 kB # grep task_struct /proc/slabinfo task_struct 2764 6832 4288 61 4 : tunables 0 0 0 : slabdata 112 112 0 Link: http://lkml.kernel.org/r/20190723151445.7385-1-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24ocfs2: fix spelling mistake "ambigous" -> "ambiguous"Gravatar Colin Ian King 1-1/+1
There is a spelling mistake in a mlog_bug_on_msg message. Fix it. Link: http://lkml.kernel.org/r/831bdff4-064e-038b-f45d-c4d265cbff1e@linux.alibaba.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24ocfs2: checkpoint appending truncate log transaction before flushingGravatar Changwei Ge 1-0/+15
Appending truncate log(TA) and and flushing truncate log(TF) are two separated transactions. They can be both committed but not checkpointed. If crash occurs then, both transaction will be replayed with several already released to global bitmap clusters. Then truncate log will be replayed resulting in cluster double free. To reproduce this issue, just crash the host while punching hole to files. Signed-off-by: Changwei Ge <gechangwei@live.cn> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24ocfs2: wait for recovering done after direct unlock requestGravatar Changwei Ge 1-4/+19
There is a scenario causing ocfs2 umount hang when multiple hosts are rebooting at the same time. NODE1 NODE2 NODE3 send unlock requset to NODE2 dies become recovery master recover NODE2 find NODE2 dead mark resource RECOVERING directly remove lock from grant list calculate usage but RECOVERING marked **miss the window of purging clear RECOVERING To reproduce this issue, crash a host and then umount ocfs2 from another node. To solve this, just let unlock progress wait for recovery done. Link: http://lkml.kernel.org/r/1550124866-20367-1-git-send-email-gechangwei@live.cn Signed-off-by: Changwei Ge <gechangwei@live.cn> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24ocfs2: delete unnecessary checks before brelse()Gravatar Markus Elfring 2-7/+3
brelse() tests whether its argument is NULL and then returns immediately. Thus the tests around the shown calls are not needed. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/55cde320-394b-f985-56ce-1a2abea782aa@web.de Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24fs/ocfs2/dir.c: remove set but not used variablesGravatar zhengbin 1-2/+1
Fixes gcc '-Wunused-but-set-variable' warning: fs/ocfs2/dir.c: In function ocfs2_dx_dir_transfer_leaf: fs/ocfs2/dir.c:3653:42: warning: variable new_list set but not used [-Wunused-but-set-variable] Link: http://lkml.kernel.org/r/1566522588-63786-4-git-send-email-joseph.qi@linux.alibaba.com Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Changwei Ge <chge@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24fs/ocfs2/file.c: remove set but not used variablesGravatar zhengbin 1-3/+0
Fixes gcc '-Wunused-but-set-variable' warning: fs/ocfs2/file.c: In function ocfs2_prepare_inode_for_write: fs/ocfs2/file.c:2143:9: warning: variable end set but not used [-Wunused-but-set-variable] Link: http://lkml.kernel.org/r/1566522588-63786-3-git-send-email-joseph.qi@linux.alibaba.com Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Changwei Ge <chge@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>