- 01 Nov, 2023 6 commits
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SeongJae Park authored
damon_sysfs_set_targets(), which updates the targets of the context for online commitment, do not remove targets that removed from the corresponding sysfs files. As a result, more than intended targets of the context can exist and hence consume memory and monitoring CPU resource more than expected. Fix it by removing all targets of the context and fill up again using the user input. This could cause unnecessary memory dealloc and realloc operations, but this is not a hot code path. Also, note that damon_target is stateless, and hence no data is lost. [sj@kernel.org: fix unnecessary monitoring results removal] Link: https://lkml.kernel.org/r/20231028213353.45397-1-sj@kernel.org Link: https://lkml.kernel.org/r/20231022210735.46409-2-sj@kernel.org Fixes: da878780 ("mm/damon/sysfs: support online inputs update") Signed-off-by:
SeongJae Park <sj@kernel.org> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: <stable@vger.kernel.org> [5.19.x] Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Nhat Pham authored
We recently encountered a bug that makes all zswap store attempt fail. Specifically, after: "141fdeec mm/zswap: delay the initialization of zswap" if we build a kernel with zswap disabled by default, then enabled after the swapfile is set up, the zswap tree will not be initialized. As a result, all zswap store calls will be short-circuited. We have to perform another swapon to get zswap working properly again. Fortunately, this issue has since been fixed by the patch that kills frontswap: "42c06a0e mm: kill frontswap" which performs zswap_swapon() unconditionally, i.e always initializing the zswap tree. This test add a sanity check that ensure zswap storing works as intended. Link: https://lkml.kernel.org/r/20231020222009.2358953-1-nphamcs@gmail.comSigned-off-by:
Nhat Pham <nphamcs@gmail.com> Acked-by:
Rik van Riel <riel@surriel.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by:
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Tom Yang authored
The "first" is spelled "fist". Link: https://lkml.kernel.org/r/20231023095737.21823-1-yangqixiao@inspur.comSigned-off-by:
Tom Yang <yangqixiao@inspur.com> Reviewed-by:
Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by:
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Baoquan He authored
LKP reported smatch warning as below: =================== smatch warnings: mm/vmalloc.c:3689 vread_iter() error: we previously assumed 'vm' could be null (see line 3667) ...... 06c89946 @3667 size = vm ? get_vm_area_size(vm) : va_size(va); ...... 06c89946 @3689 else if (!(vm->flags & VM_IOREMAP)) ^^^^^^^^^ Unchecked dereference ===================== This is not a runtime bug because the possible null 'vm' in the pointed place could only happen when flags == VMAP_BLOCK. However, the case 'flags == VMAP_BLOCK' should never happen and has been detected with WARN_ON. Please check vm_map_ram() implementation and the earlier checking in vread_iter() at below: ~~~~~~~~~~~~~~~~~~~~~~~~~~ /* * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need * be set together with VMAP_RAM. */ WARN_ON(flags == VMAP_BLOCK); if (!vm && !flags) continue; ~~~~~~~~~~~~~~~~~~~~~~~~~~ So add checking on whether 'vm' could be null when dereferencing it in vread_iter(). This mutes smatch complaint. Link: https://lkml.kernel.org/r/ZTCURc8ZQE+KrTvS@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/ZS/2k6DIMd0tZRgK@MiWiFi-R3L-srvSigned-off-by:
Baoquan He <bhe@redhat.com> Reported-by:
kernel test robot <lkp@intel.com> Reported-by:
Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202310171600.WCrsOwFj-lkp@intel.com/ Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Philip Li <philip.li@intel.com> Signed-off-by:
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Nhat Pham authored
During a zswap store attempt, the compression algorithm could fail (for e.g due to the page containing incompressible random data). This is not tracked in any of existing zswap counters, making it hard to monitor for and investigate. We have run into this problem several times in our internal investigations on zswap store failures. This patch adds a dedicated debugfs counter for compression algorithm failures. Link: https://lkml.kernel.org/r/20231024234509.2680539-1-nphamcs@gmail.comSigned-off-by:
Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Andrey Konovalov authored
Drop "the" from the title of the documentation article for UBSAN, as it is redundant. Also add SPDX-License-Identifier for ubsan.rst. Link: https://lkml.kernel.org/r/5fb11a4743eea9d9232a5284dea0716589088fec.1698161845.git.andreyknvl@google.comSigned-off-by:
Andrey Konovalov <andreyknvl@google.com> Reviewed-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by:
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- 25 Oct, 2023 34 commits
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Hugh Dickins authored
Improve alloc_migration_target_by_mpol()'s treatment of MPOL_INTERLEAVE. Make an effort in do_mbind(), to identify the correct interleave index for the first page to be migrated, so that it and all subsequent pages from the same vma will be targeted to precisely their intended nodes. Pages from following vmas will still be interleaved from the requested nodemask, but perhaps starting from a different base. Whether this is worth doing at all, or worth improving further, is arguable: queue_folio_required() is right not to care about the precise placement on interleaved nodes; but this little effort seems appropriate. [hughd@google.com: do vma_iter search under mmap_write_unlock()] Link: https://lkml.kernel.org/r/3311d544-fb05-a7f1-1b74-16aa0f6cd4fe@google.com Link: https://lkml.kernel.org/r/77954a5-9c9b-1c11-7d5c-3262c01b895f@google.comSigned-off-by:
Hugh Dickins <hughd@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun heo <tj@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Hugh Dickins authored
mbind(2) holds down_write of current task's mmap_lock throughout (exclusive because it needs to set the new mempolicy on the vmas); migrate_pages(2) holds down_read of pid's mmap_lock throughout. They both hold mmap_lock across the internal migrate_pages(), under which all new page allocations (huge or small) are made. I'm nervous about it; and migrate_pages() certainly does not need mmap_lock itself. It's done this way for mbind(2), because its page allocator is vma_alloc_folio() or alloc_hugetlb_folio_vma(), both of which depend on vma and address. Now that we have alloc_pages_mpol(), depending on (refcounted) memory policy and interleave index, mbind(2) can be modified to use that or alloc_hugetlb_folio_nodemask(), and then not need mmap_lock across the internal migrate_pages() at all: add alloc_migration_target_by_mpol() to replace mbind's new_page(). (After that change, alloc_hugetlb_folio_vma() is used by nothing but a userfaultfd function: move it out of hugetlb.h and into the #ifdef.) migrate_pages(2) has chosen its target node before migrating, so can continue to use the standard alloc_migration_target(); but let it take and drop mmap_lock just around migrate_to_node()'s queue_pages_range(): neither the node-to-node calculations nor the page migrations need it. It seems unlikely, but it is conceivable that some userspace depends on the kernel's mmap_lock exclusion here, instead of doing its own locking: more likely in a testsuite than in real life. It is also possible, of course, that some pages on the list will be munmapped by another thread before they are migrated, or a newer memory policy applied to the range by that time: but such races could happen before, as soon as mmap_lock was dropped, so it does not appear to be a concern. Link: https://lkml.kernel.org/r/21e564e8-269f-6a89-7ee2-fd612831c289@google.comSigned-off-by:
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Hugh Dickins authored
Shrink shmem's stack usage by eliminating the pseudo-vma from its folio allocation. alloc_pages_mpol(gfp, order, pol, ilx, nid) becomes the principal actor for passing mempolicy choice down to __alloc_pages(), rather than vma_alloc_folio(gfp, order, vma, addr, hugepage). vma_alloc_folio() and alloc_pages() remain, but as wrappers around alloc_pages_mpol(). alloc_pages_bulk_*() untouched, except to provide the additional args to policy_nodemask(), which subsumes policy_node(). Cleanup throughout, cutting out some unhelpful "helpers". It would all be much simpler without MPOL_INTERLEAVE, but that adds a dynamic to the constant mpol: complicated by v3.6 commit 09c231cb ("tmpfs: distribute interleave better across nodes"), which added ino bias to the interleave, hidden from mm/mempolicy.c until this commit. Hence "ilx" throughout, the "interleave index". Originally I thought it could be done just with nid, but that's wrong: the nodemask may come from the shared policy layer below a shmem vma, or it may come from the task layer above a shmem vma; and without the final nodemask then nodeid cannot be decided. And how ilx is applied depends also on page order. The interleave index is almost always irrelevant unless MPOL_INTERLEAVE: with one exception in alloc_pages_mpol(), where the NO_INTERLEAVE_INDEX passed down from vma-less alloc_pages() is also used as hint not to use THP-style hugepage allocation - to avoid the overhead of a hugepage arg (though I don't understand why we never just added a GFP bit for THP - if it actually needs a different allocation strategy from other pages of the same order). vma_alloc_folio() still carries its hugepage arg here, but it is not used, and should be removed when agreed. get_vma_policy() no longer allows a NULL vma: over time I believe we've eradicated all the places which used to need it e.g. swapoff and madvise used to pass NULL vma to read_swap_cache_async(), but now know the vma. [hughd@google.com: handle NULL mpol being passed to __read_swap_cache_async()] Link: https://lkml.kernel.org/r/ea419956-4751-0102-21f7-9c93cb957892@google.com Link: https://lkml.kernel.org/r/74e34633-6060-f5e3-aee-7040d43f2e93@google.com Link: https://lkml.kernel.org/r/1738368e-bac0-fd11-ed7f-b87142a939fe@google.comSigned-off-by:
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Hugh Dickins authored
folio_prep_large_rmappable() is being used repeatedly along with a conversion from page to folio, a check non-NULL, a check order > 1: wrap it all up into struct folio *page_rmappable_folio(struct page *). Link: https://lkml.kernel.org/r/8d92c6cf-eebe-748-e29c-c8ab224c741@google.comSigned-off-by:
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Hugh Dickins authored
v3.8 commit b24f53a0 ("mm: mempolicy: Add MPOL_MF_LAZY") introduced MPOL_MF_LAZY, and included it in the MPOL_MF_VALID flags; but a720094d ("mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now") immediately removed it from MPOL_MF_VALID flags, pending further review. "This will need to be revisited", but it has not been reinstated. The present state is confusing: there is dead code in mm/mempolicy.c to handle MPOL_MF_LAZY cases which can never occur. Remove that: it can be resurrected later if necessary. But keep the definition of MPOL_MF_LAZY, which must remain in the UAPI, even though it always fails with EINVAL. https://lore.kernel.org/linux-mm/1553041659-46787-1-git-send-email-yang.shi@linux.alibaba.com/ links to a previous request to remove MPOL_MF_LAZY. Link: https://lkml.kernel.org/r/80c9665c-1c3f-17ba-21a3-f6115cebf7d@google.comSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun heo <tj@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Hugh Dickins authored
mpol_shared_policy_init() does not need to use a pseudo-vma: it can use sp_alloc() and sp_insert() directly, since the object's shared policy tree is empty and inaccessible (needing no lock) at get_inode() time. Link: https://lkml.kernel.org/r/3bef62d8-ae78-4c2-533-56a44ae425c@google.comSigned-off-by:
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Hugh Dickins authored
Prefer the more explicit "pgoff_t" to "unsigned long" when dealing with a shared mempolicy tree. Delete confusing comment about pseudo mm vmas. Link: https://lkml.kernel.org/r/5451157-3818-4af5-fd2c-5d26a5d1dc53@google.comSigned-off-by:
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Hugh Dickins authored
Before getting down to work, do a little cleanup, mainly of inconsistent variable naming. I gave up trying to rationalize mpol versus pol versus policy, and node versus nid, but let's avoid p and nd. Remove a few superfluous blank lines, but add one; and here prefer vma->vm_policy to vma_policy(vma) - the latter being appropriate in other sources, which have to allow for !CONFIG_NUMA. That intriguing line about KERNEL_DS? should have gone in v2.6.15, when numa_policy_init() stopped using set_mempolicy(2)'s system call handler. Link: https://lkml.kernel.org/r/68287974-b6ae-7df-4ba-d19ddd69cbf@google.comSigned-off-by:
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Hugh Dickins authored
Delete those ancient pr_debug()s - PDprintk()s in Andi Kleen's original submission of core NUMA API, and useful when debugging shared mempolicy lifetime back then, but not used recently. Link: https://lkml.kernel.org/r/f25135-ffb2-40d8-9577-720772b333@google.comSigned-off-by:
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Hugh Dickins authored
"man 2 migrate_pages" says "On success migrate_pages() returns the number of pages that could not be moved". Although 5.3 and 5.4 commits fixed mbind(MPOL_MF_STRICT|MPOL_MF_MOVE*) to fail with EIO when not all pages could be moved (because some could not be isolated for migration), migrate_pages(2) was left still reporting only those pages failing at the migration stage, forgetting those failing at the earlier isolation stage. Fix that by accumulating a long nr_failed count in struct queue_pages, returned by queue_pages_range() when it's not returning an error, for adding on to the nr_failed count from migrate_pages() in mm/migrate.c. A count of pages? It's more a count of folios, but changing it to pages would entail more work (also in mm/migrate.c): does not seem justified. queue_pages_range() itself should only return -EIO in the "strictly unmovable" case (STRICT without any MOVEs): in that case it's best to break out as soon as nr_failed gets set; but otherwise it should continue to isolate pages for MOVing even when nr_failed - as the mbind(2) manpage promises. There's a case when nr_failed should be incremented when it was missed: queue_folios_pte_range() and queue_folios_hugetlb() count the transient migration entries, like queue_folios_pmd() already did. And there's a case when nr_failed should not be incremented when it would have been: in meeting later PTEs of the same large folio, which can only be isolated once: fixed by recording the current large folio in struct queue_pages. Clean up the affected functions, fixing or updating many comments. Bool migrate_folio_add(), without -EIO: true if adding, or if skipping shared (but its arguable folio_estimated_sharers() heuristic left unchanged). Use MPOL_MF_WRLOCK flag to queue_pages_range(), instead of bool lock_vma. Use explicit STRICT|MOVE* flags where queue_pages_test_walk() checks for skipping, instead of hiding them behind MPOL_MF_VALID. Link: https://lkml.kernel.org/r/9a6b0b9-3bb-dbef-8adf-efab4397b8d@google.comSigned-off-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun heo <tj@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Hugh Dickins authored
It seems strange that kernfs should be an outlier with a set_policy and get_policy in its kernfs_vm_ops. Ah, it dates back to v2.6.30's commit 095160ae ("sysfs: fix some bin_vm_ops errors"), when I had crashed on powerpc's pci_mmap_legacy_page_range() fallback to shmem_zero_setup(). Well, that was commendably thorough, to give sysfs-bin a set_policy and get_policy, just to avoid the way it was coded resulting in EINVAL from mmap when CONFIG_NUMA; but somehow feels a bit over-the-top to me now. It's easier to say that nobody should expect to manage a shmem object's shared NUMA mempolicy via some kernfs backdoor to that object: delete that code (and there's no longer an EINVAL from mmap in the NUMA case). This then leaves set_policy/get_policy as implemented only by shmem - though importantly also by SysV SHM, which has to interface with shmem which implements them, and with SHM_HUGETLB which does not. Link: https://lkml.kernel.org/r/302164-a760-4a9e-879b-6870c9b4013@google.comSigned-off-by:
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Hugh Dickins authored
Patch series "mempolicy: cleanups leading to NUMA mpol without vma", v2. Mostly cleanups in mm/mempolicy.c, but finally removing the pseudo-vma from shmem folio allocation, and removing the mmap_lock around folio migration for mbind and migrate_pages syscalls. This patch (of 12): hugetlbfs_fallocate() goes through the motions of pasting a shared NUMA mempolicy onto its pseudo-vma, but how could there ever be a shared NUMA mempolicy for this file? hugetlb_vm_ops has never offered a set_policy method, and hugetlbfs_parse_param() has never supported any mpol options for a mount-wide default policy. It's just an illusion: clean it away so as not to confuse others, giving us more freedom to adjust shmem's set_policy/get_policy implementation. But hugetlbfs_inode_info is still required, just to accommodate seals. Yes, shared NUMA mempolicy support could be added to hugetlbfs, with a set_policy method and/or mpol mount option (Andi's first posting did include an admitted-unsatisfactory hugetlb_set_policy()); but it seems that nobody has bothered to add that in the nineteen years since v2.6.7 made it possible, and there is at least one company that has invested enough into hugetlbfs, that I guess they have learnt well enough how to manage its NUMA, without needing shared mempolicy. Remove linux/mempolicy.h from linux/hugetlb.h: include linux/pagemap.h in its place, because hugetlb.h's recently added use of filemap_lock_folio() requires that (although most .configs and .c's get it in some other way). Link: https://lkml.kernel.org/r/ebc0987e-beff-8bfb-9283-234c2cbd17c5@google.com Link: https://lkml.kernel.org/r/cae82d4b-904a-faaf-282a-34fcc188c81f@google.comSigned-off-by:
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SeongJae Park authored
damon_sysfs_set_targets() had a bug that can result in unexpected memory usage and monitoring overhead increase. The bug has fixed by a previous commit. Add a unit test for avoiding a similar bug of future. Link: https://lkml.kernel.org/r/20231022210735.46409-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
When calculating the pseudo-moving access rate, DAMON divides some values by the maximum nr_accesses. However, due to the type of the related variables, simple division-based calculation of the divisor can return zero. As a result, divide-by-zero is possible. Fix it by using damon_max_nr_accesses(), which handles the case. Note that this is a fix for a commit that not in the mainline but mm tree. Link: https://lkml.kernel.org/r/20231019194924.100347-6-sj@kernel.org Fixes: ace30fb2 ("mm/damon/core: use pseudo-moving sum for nr_accesses_bp") Reported-by:
Jakub Acs <acsjakub@amazon.de> Signed-off-by:
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SeongJae Park authored
When calculating the hotness threshold for lru_prio scheme of DAMON_LRU_SORT, the module divides some values by the maximum nr_accesses. However, due to the type of the related variables, simple division-based calculation of the divisor can return zero. As a result, divide-by-zero is possible. Fix it by using damon_max_nr_accesses(), which handles the case. Link: https://lkml.kernel.org/r/20231019194924.100347-5-sj@kernel.org Fixes: 40e983cc ("mm/damon: introduce DAMON-based LRU-lists Sorting") Signed-off-by:
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SeongJae Park authored
When calculating the hotness of each region for the under-quota regions prioritization, DAMON divides some values by the maximum nr_accesses. However, due to the type of the related variables, simple division-based calculation of the divisor can return zero. As a result, divide-by-zero is possible. Fix it by using damon_max_nr_accesses(), which handles the case. Link: https://lkml.kernel.org/r/20231019194924.100347-4-sj@kernel.org Fixes: 198f0f4c ("mm/damon/vaddr,paddr: support pageout prioritization") Signed-off-by:
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SeongJae Park authored
When monitoring attributes are changed, DAMON updates access rate of the monitoring results accordingly. For that, it divides some values by the maximum nr_accesses. However, due to the type of the related variables, simple division-based calculation of the divisor can return zero. As a result, divide-by-zero is possible. Fix it by using damon_max_nr_accesses(), which handles the case. Link: https://lkml.kernel.org/r/20231019194924.100347-3-sj@kernel.org Fixes: 2f5bef5a ("mm/damon/core: update monitoring results for new monitoring attributes") Signed-off-by:
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SeongJae Park authored
Patch series "avoid divide-by-zero due to max_nr_accesses overflow". The maximum nr_accesses of given DAMON context can be calculated by dividing the aggregation interval by the sampling interval. Some logics in DAMON uses the maximum nr_accesses as a divisor. Hence, the value shouldn't be zero. Such case is avoided since DAMON avoids setting the agregation interval as samller than the sampling interval. However, since nr_accesses is unsigned int while the intervals are unsigned long, the maximum nr_accesses could be zero while casting. Avoid the divide-by-zero by implementing a function that handles the corner case (first patch), and replaces the vulnerable direct max nr_accesses calculations (remaining patches). Note that the patches for the replacements are divided for broken commits, to make backporting on required tres easier. Especially, the last patch is for a patch that not yet merged into the mainline but in mm tree. This patch (of 4): The maximum nr_accesses of given DAMON context can be calculated by dividing the aggregation interval by the sampling interval. Some logics in DAMON uses the maximum nr_accesses as a divisor. Hence, the value shouldn't be zero. Such case is avoided since DAMON avoids setting the agregation interval as samller than the sampling interval. However, since nr_accesses is unsigned int while the intervals are unsigned long, the maximum nr_accesses could be zero while casting. Implement a function that handles the corner case. Note that this commit is not fixing the real issue since this is only introducing the safe function that will replaces the problematic divisions. The replacements will be made by followup commits, to make backporting on stable series easier. Link: https://lkml.kernel.org/r/20231019194924.100347-1-sj@kernel.org Link: https://lkml.kernel.org/r/20231019194924.100347-2-sj@kernel.org Fixes: 198f0f4c ("mm/damon/vaddr,paddr: support pageout prioritization") Signed-off-by:
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Hugh Dickins authored
Since commit dc68badc ("mm: mlock: update mlock_pte_range to handle large folio") I've just occasionally seen VM_WARN_ON_FOLIO(folio_test_ksm) warnings from folio_within_range(), in a splurge after testing with KSM hyperactive. folio_referenced_one()'s use of folio_within_vma() is safe because it checks folio_test_large() first; but allow_mlock_munlock() needs to do the same to avoid those warnings (or check !folio_test_ksm() itself? Or move either check into folio_within_range()? Hard to tell without more examples of its use). Link: https://lkml.kernel.org/r/23852f6a-5bfa-1ffd-30db-30c5560ad426@google.com Fixes: dc68badc ("mm: mlock: update mlock_pte_range to handle large folio") Signed-off-by:
Yin Fengwei <fengwei.yin@intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Stefan Roesch <shr@devkernel.io> Signed-off-by:
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Hugh Dickins authored
Since commit e509ad4d ("ext4: use bdev_getblk() to avoid memory reclaim in readahead path") rightly replaced GFP_NOFAIL allocations by GFP_NOWAIT allocations, I've occasionally been seeing "page allocation failure: order:0" warnings under load: all with ext4_sb_breadahead_unmovable() in the stack. I don't think those warnings are of any interest: suppress them with __GFP_NOWARN. Link: https://lkml.kernel.org/r/7bc6ad16-9a4d-dd90-202e-47d6cbb5a136@google.com Fixes: e509ad4d ("ext4: use bdev_getblk() to avoid memory reclaim in readahead path") Signed-off-by:
Jan Kara <jack@suse.cz> Cc: Hui Zhu <teawater@antgroup.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by:
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Baolin Wang authored
When doing compaction, I found the lru_add_drain() is an obvious hotspot when migrating pages. The distribution of this hotspot is as follows: - 18.75% compact_zone - 17.39% migrate_pages - 13.79% migrate_pages_batch - 11.66% migrate_folio_move - 7.02% lru_add_drain + 7.02% lru_add_drain_cpu + 3.00% move_to_new_folio 1.23% rmap_walk + 1.92% migrate_folio_unmap + 3.20% migrate_pages_sync + 0.90% isolate_migratepages The lru_add_drain() was added by commit c3096e67 ("mm/migrate: __unmap_and_move() push good newpage to LRU") to drain the newpage to LRU immediately, to help to build up the correct newpage->mlock_count in remove_migration_ptes() for mlocked pages. However, if there are no mlocked pages are migrating, then we can avoid this lru drain operation, especailly for the heavy concurrent scenarios. So we can record the source pages' mlocked status in migrate_folio_unmap(), and only drain the lru list when the mlocked status is set in migrate_folio_move(). In addition, the page was already isolated from lru when migrating, so checking the mlocked status is stable by folio_test_mlocked() in migrate_folio_unmap(). After this patch, I can see the hotpot of the lru_add_drain() is gone: - 9.41% migrate_pages_batch - 6.15% migrate_folio_move - 3.64% move_to_new_folio + 1.80% migrate_folio_extra + 1.70% buffer_migrate_folio + 1.41% rmap_walk + 0.62% folio_add_lru + 3.07% migrate_folio_unmap Meanwhile, the compaction latency shows some improvements when running thpscale: base patched Amean fault-both-1 1131.22 ( 0.00%) 1112.55 * 1.65%* Amean fault-both-3 2489.75 ( 0.00%) 2324.15 * 6.65%* Amean fault-both-5 3257.37 ( 0.00%) 3183.18 * 2.28%* Amean fault-both-7 4257.99 ( 0.00%) 4079.04 * 4.20%* Amean fault-both-12 6614.02 ( 0.00%) 6075.60 * 8.14%* Amean fault-both-18 10607.78 ( 0.00%) 8978.86 * 15.36%* Amean fault-both-24 14911.65 ( 0.00%) 11619.55 * 22.08%* Amean fault-both-30 14954.67 ( 0.00%) 14925.66 * 0.19%* Amean fault-both-32 16654.87 ( 0.00%) 15580.31 * 6.45%* Link: https://lkml.kernel.org/r/06e9153a7a4850352ec36602df3a3a844de45698.1697859741.git.baolin.wang@linux.alibaba.comSigned-off-by:Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by:
Zi Yan <ziy@nvidia.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by:
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Vegard Nossum authored
The directory this file is in was renamed but the reference didn't get updated. Fix it. Link: https://lkml.kernel.org/r/20231022185619.919397-1-vegard.nossum@oracle.com Fixes: ee65728e ("docs: rename Documentation/vm to Documentation/mm") Signed-off-by:
Vegard Nossum <vegard.nossum@oracle.com> Acked-by:
Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by:
Muchun Song <songmuchun@bytedance.com> Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Wu XiangCheng <bobwxc@email.cn> Signed-off-by:
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Hyesoo Yu authored
For compound pages, the head sets the PG_head flag and the tail sets the compound_head to indicate the head page. If a user allocates a compound page and frees it with a different order, the compound page information will not be properly initialized. To detect this problem, compound_order(page) and the order argument are compared, but this is not checked when the order argument is zero. That error should be checked regardless of the order. Link: https://lkml.kernel.org/r/20231023083217.1866451-1-hyesoo.yu@samsung.comSigned-off-by:
Hyesoo Yu <hyesoo.yu@samsung.com> Reviewed-by:
Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by:
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Muhammad Muzammil authored
Link: https://lkml.kernel.org/r/20231023124405.36981-1-m.muzzammilashraf@gmail.comSigned-off-by:
Muhammad Muzammil <m.muzzammilashraf@gmail.com> Reviewed-by:
Randy Dunlap <rdunlap@infradead.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muhammad Muzammil <m.muzzammilashraf@gmail.com> Signed-off-by:
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Vishal Moola (Oracle) authored
This removes 2 calls to compound_head() and helps convert khugepaged to use folios throughout. Previously, if the address passed to collapse_pte_mapped_thp() corresponded to a tail page, the scan would fail immediately. Using filemap_lock_folio() we get the corresponding folio back and try to operate on the folio instead. Link: https://lkml.kernel.org/r/20231020183331.10770-6-vishal.moola@gmail.comSigned-off-by:
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Vishal Moola (Oracle) authored
Also remove count_memcg_page_event now that its last caller no longer uses it and reword hpage_collapse_alloc_page() to hpage_collapse_alloc_folio(). This removes 1 call to compound_head() and helps convert khugepaged to use folios throughout. Link: https://lkml.kernel.org/r/20231020183331.10770-5-vishal.moola@gmail.comSigned-off-by:
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Vishal Moola (Oracle) authored
Both callers of is_refcount_suitable() have been converted to use folios, so convert it to take in a folio. Both callers only operate on head pages of folios so mapcount/refcount conversions here are trivial. Removes 3 calls to compound head, and removes 315 bytes of kernel text. Link: https://lkml.kernel.org/r/20231020183331.10770-4-vishal.moola@gmail.comSigned-off-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
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Vishal Moola (Oracle) authored
Replaces 5 calls to compound_head(), and removes 1385 bytes of kernel text. Link: https://lkml.kernel.org/r/20231020183331.10770-3-vishal.moola@gmail.comSigned-off-by:
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Vishal Moola (Oracle) authored
Patch series "Some khugepaged folio conversions", v3. This patchset converts a number of functions to use folios. This cleans up some khugepaged code and removes a large number of hidden compound_head() calls. This patch (of 5): Replaces 11 calls to compound_head() with 1, and removes 1348 bytes of kernel text. Link: https://lkml.kernel.org/r/20231020183331.10770-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20231020183331.10770-2-vishal.moola@gmail.comSigned-off-by:
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Qi Zheng authored
In offline_pages(), if a node becomes memoryless, we will clear its N_MEMORY state by calling node_states_clear_node(). But we do this after rebuilding the zonelists by calling build_all_zonelists(), which will cause this memoryless node to still be in the fallback nodes (node_order[]) of other nodes. To drop memoryless nodes from fallback nodes in this case, just call node_states_clear_node() before calling build_all_zonelists(). In this way, we will not try to allocate pages from memoryless node0, then the panic mentioned in [1] will also be fixed. Even though this problem has been solved by dropping the NODE_MIN_SIZE constrain in x86 [2], it would be better to fix it in the core MM as well. https://lore.kernel.org/all/20230212110305.93670-1-zhengqi.arch@bytedance.com/ [1] https://lore.kernel.org/all/20231017062215.171670-1-rppt@kernel.org/ [2] Link: https://lkml.kernel.org/r/9f1dbe7ee1301c7163b2770e32954ff5e3ecf2c4.1697711415.git.zhengqi.arch@bytedance.comSigned-off-by:
Qi Zheng <zhengqi.arch@bytedance.com> Acked-by:
Ingo Molnar <mingo@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Qi Zheng authored
Patch series "handle memoryless nodes more appropriately", v3. Currently, in the process of initialization or offline memory, memoryless nodes will still be built into the fallback list of itself or other nodes. This is not what we expected, so this patch series removes memoryless nodes from the fallback list entirely. This patch (of 2): In find_next_best_node(), we skipped the memoryless nodes when building the zonelists of other normal nodes (N_NORMAL), but did not skip the memoryless node itself when building the zonelist. This will cause it to be traversed at runtime. For example, say we have node0 and node1, node0 is memoryless node, then the fallback order of node0 and node1 as follows: [ 0.153005] Fallback order for Node 0: 0 1 [ 0.153564] Fallback order for Node 1: 1 After this patch, we skip memoryless node0 entirely, then the fallback order of node0 and node1 as follows: [ 0.155236] Fallback order for Node 0: 1 [ 0.155806] Fallback order for Node 1: 1 So it becomes completely invisible, which will reduce runtime overhead. And in this way, we will not try to allocate pages from memoryless node0, then the panic mentioned in [1] will also be fixed. Even though this problem has been solved by dropping the NODE_MIN_SIZE constrain in x86 [2], it would be better to fix it in core MM as well. [1]. https://lore.kernel.org/all/20230212110305.93670-1-zhengqi.arch@bytedance.com/ [2]. https://lore.kernel.org/all/20231017062215.171670-1-rppt@kernel.org/ [zhengqi.arch@bytedance.com: update comment, per Ingo] Link: https://lkml.kernel.org/r/7300fc00a057eefeb9a68c8ad28171c3f0ce66ce.1697799303.git.zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/cover.1697799303.git.zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/cover.1697711415.git.zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/157013e978468241de4a4c05d5337a44638ecb0e.1697711415.git.zhengqi.arch@bytedance.comSigned-off-by:
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Zi Yan authored
Add nr_split to trace_mm_migrate_pages for large folio (including THP) split events. [akpm@linux-foundation.org: cleanup per Huang, Ying] Link: https://lkml.kernel.org/r/20231017163129.2025214-2-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
nr_failed was missing the large folio splits from migrate_pages_batch() and can cause a mismatch between migrate_pages() return value and the number of not migrated pages, i.e., when the return value of migrate_pages() is 0, there are still pages left in the from page list. It will happen when a non-PMD THP large folio fails to migrate due to -ENOMEM and is split successfully but not all the split pages are not migrated, migrate_pages_batch() would return non-zero, but astats.nr_thp_split = 0. nr_failed would be 0 and returned to the caller of migrate_pages(), but the not migrated pages are left in the from page list without being added back to LRU lists. Fix it by adding a new nr_split counter for large folio splits and adding it to nr_failed in migrate_page_sync() after migrate_pages_batch() is done. Link: https://lkml.kernel.org/r/20231017163129.2025214-1-zi.yan@sent.com Fixes: 2ef7dbb2 ("migrate_pages: try migrate in batch asynchronously firstly") Signed-off-by:
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Liu Shixin authored
In patch (mm: kmemleak: split __create_object into two functions), the initialisation of object has been splited in two places. Catalin said it feels a bit weird and error prone. So leave __alloc_object() to just do the actual allocation and let __link_object() do the full initialisation. Link: https://lkml.kernel.org/r/20231023025125.90972-1-liushixin2@huawei.comSigned-off-by:
Liu Shixin <liushixin2@huawei.com> Suggested-by:
Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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