mm-commits Archive on lore.kernel.org
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From: Andrew Morton <akpm@linux-foundation.org>
To: alex.williamson@redhat.com, bmt@zurich.ibm.com,
	cohuck@redhat.com, daniel.m.jordan@oracle.com, dbueso@suse.de,
	dledford@redhat.com, fly@kernel.page, hughd@google.com,
	jgg@ziepe.ca, jglisse@redhat.com, jhubbard@nvidia.com,
	kirill.shutemov@linux.intel.com, ldufour@linux.ibm.com,
	Liam.Howlett@oracle.com, mm-commits@vger.kernel.org,
	peterz@infradead.org, rientjes@google.com, vbabka@suse.cz,
	walken@google.com, willy@infradead.org, yinghan@google.com
Subject: + mm-util-account_locked_vm-does-not-hold-mmap_lock.patch added to -mm tree
Date: Mon, 27 Jul 2020 13:34:27 -0700
Message-ID: <20200727203427.4q1kvBOcr%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200723211432.b31831a0df3bc2cbdae31b40@linux-foundation.org>


The patch titled
     Subject: mm, util: account_locked_vm() does not hold mmap_lock
has been added to the -mm tree.  Its filename is
     mm-util-account_locked_vm-does-not-hold-mmap_lock.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-util-account_locked_vm-does-not-hold-mmap_lock.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-util-account_locked_vm-does-not-hold-mmap_lock.patch

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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Pengfei Li <fly@kernel.page>
Subject: mm, util: account_locked_vm() does not hold mmap_lock

Since mm->locked_vm is already an atomic counter, account_locked_vm()
does not need to hold mmap_lock.

Link: http://lkml.kernel.org/r/20200726080224.205470-2-fly@kernel.page
Signed-off-by: Pengfei Li <fly@kernel.page>
Cc: Bernard Metzler <bmt@zurich.ibm.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/vfio/vfio_iommu_type1.c |    8 ++------
 mm/util.c                       |   15 +++------------
 2 files changed, 5 insertions(+), 18 deletions(-)

--- a/drivers/vfio/vfio_iommu_type1.c~mm-util-account_locked_vm-does-not-hold-mmap_lock
+++ a/drivers/vfio/vfio_iommu_type1.c
@@ -376,12 +376,8 @@ static int vfio_lock_acct(struct vfio_dm
 	if (!mm)
 		return -ESRCH; /* process exited */
 
-	ret = mmap_write_lock_killable(mm);
-	if (!ret) {
-		ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task,
-					  dma->lock_cap);
-		mmap_write_unlock(mm);
-	}
+	ret = __account_locked_vm(mm, abs(npage), npage > 0,
+					dma->task, dma->lock_cap);
 
 	if (async)
 		mmput(mm);
--- a/mm/util.c~mm-util-account_locked_vm-does-not-hold-mmap_lock
+++ a/mm/util.c
@@ -424,8 +424,7 @@ void arch_pick_mmap_layout(struct mm_str
  * @task:        task used to check RLIMIT_MEMLOCK
  * @bypass_rlim: %true if checking RLIMIT_MEMLOCK should be skipped
  *
- * Assumes @task and @mm are valid (i.e. at least one reference on each), and
- * that mmap_lock is held as writer.
+ * Assumes @task and @mm are valid (i.e. at least one reference on each).
  *
  * Return:
  * * 0       on success
@@ -437,8 +436,6 @@ int __account_locked_vm(struct mm_struct
 	unsigned long locked_vm, limit;
 	int ret = 0;
 
-	mmap_assert_write_locked(mm);
-
 	locked_vm = atomic64_read(&mm->locked_vm);
 	if (inc) {
 		if (!bypass_rlim) {
@@ -476,17 +473,11 @@ EXPORT_SYMBOL_GPL(__account_locked_vm);
  */
 int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc)
 {
-	int ret;
-
 	if (pages == 0 || !mm)
 		return 0;
 
-	mmap_write_lock(mm);
-	ret = __account_locked_vm(mm, pages, inc, current,
-				  capable(CAP_IPC_LOCK));
-	mmap_write_unlock(mm);
-
-	return ret;
+	return __account_locked_vm(mm, pages, inc,
+					current, capable(CAP_IPC_LOCK));
 }
 EXPORT_SYMBOL_GPL(account_locked_vm);
 
_

Patches currently in -mm which might be from fly@kernel.page are

mm-make-mm-locked_vm-an-atomic64-counter.patch
mm-util-account_locked_vm-does-not-hold-mmap_lock.patch


  parent reply index

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-24  4:14 incoming Andrew Morton
2020-07-24  4:15 ` [patch 01/15] mm/memory.c: avoid access flag update TLB flush for retried page fault Andrew Morton
     [not found]   ` <30cf7356-bef1-c621-60cb-e12a8bd9111d@linux.alibaba.com>
2020-07-24  4:56     ` Andrew Morton
2020-07-24  4:15 ` [patch 02/15] mm/mmap.c: close race between munmap() and expand_upwards()/downwards() Andrew Morton
2020-07-24  4:15 ` [patch 03/15] vfs/xattr: mm/shmem: kernfs: release simple xattr entry in a right way Andrew Morton
2020-07-24  4:15 ` [patch 04/15] mm: initialize return of vm_insert_pages Andrew Morton
2020-07-24  4:15 ` [patch 05/15] mm/memcontrol: fix OOPS inside mem_cgroup_get_nr_swap_pages() Andrew Morton
2020-07-24  4:15 ` [patch 06/15] mm/memcg: fix refcount error while moving and swapping Andrew Morton
2020-07-24  4:15 ` [patch 07/15] mm: memcg/slab: fix memory leak at non-root kmem_cache destroy Andrew Morton
2020-07-24  4:15 ` [patch 08/15] mm/hugetlb: avoid hardcoding while checking if cma is enabled Andrew Morton
2020-07-24  4:15 ` [patch 09/15] khugepaged: fix null-pointer dereference due to race Andrew Morton
2020-07-24  4:15 ` [patch 10/15] mailmap: add entry for Mike Rapoport Andrew Morton
2020-07-24  4:15 ` [patch 11/15] squashfs: fix length field overlap check in metadata reading Andrew Morton
2020-07-24  4:15 ` [patch 12/15] scripts/decode_stacktrace: strip basepath from all paths Andrew Morton
2020-07-24  4:15 ` [patch 13/15] io-mapping: indicate mapping failure Andrew Morton
2020-07-24  4:15 ` [patch 14/15] MAINTAINERS: add KCOV section Andrew Morton
2020-07-24  4:15 ` [patch 15/15] scripts/gdb: fix lx-symbols 'gdb.error' while loading modules Andrew Morton
2020-07-27 19:47 ` + mm-remove-unnecessary-wrapper-function-do_mmap_pgoff.patch added to -mm tree Andrew Morton
2020-07-27 19:56 ` + nilfs2-only-call-unlock_new_inode-if-i_new.patch " Andrew Morton
2020-07-27 19:57 ` + nilfs2-convert-__nilfs_msg-to-integrate-the-level-and-format.patch " Andrew Morton
2020-07-27 19:57 ` + nilfs2-use-a-more-common-logging-style.patch " Andrew Morton
2020-07-27 19:58 ` + checkpatch-add-test-for-repeated-words.patch " Andrew Morton
2020-07-27 20:05 ` + ocfs2-replace-http-links-with-https-ones.patch " Andrew Morton
2020-07-27 20:09 ` + ocfs2-fix-unbalanced-locking.patch " Andrew Morton
2020-07-27 20:10 ` + kernelh-remove-duplicate-include-of-asm-div64h.patch " Andrew Morton
2020-07-27 20:11 ` + tools-replace-http-links-with-https-ones.patch " Andrew Morton
2020-07-27 20:12 ` + lib-replace-http-links-with-https-ones.patch " Andrew Morton
2020-07-27 20:12 ` + include-replace-http-links-with-https-ones.patch " Andrew Morton
2020-07-27 20:34 ` + mm-make-mm-locked_vm-an-atomic64-counter.patch " Andrew Morton
2020-07-27 20:34 ` Andrew Morton [this message]
2020-07-27 20:37 ` + cg_read_strcmp-fix-null-pointer-dereference.patch " Andrew Morton
2020-07-27 20:51 ` + mm-hugetlb-add-mempolicy-check-in-the-reservation-routine.patch " Andrew Morton
2020-07-27 20:52 ` [withdrawn] checkpatch-support-deprecated-terms-checking.patch removed from " Andrew Morton
2020-07-27 23:47 ` [obsolete] scripts-deprecated_terms-recommend-denylist-allowlist-instead-of-blacklist-whitelist.patch " Andrew Morton
2020-07-27 23:50 ` [obsolete] scripts-deprecated_terms-sync-with-inclusive-terms.patch " Andrew Morton
2020-07-28  0:18 ` [failures] mm-hugetlb-add-mempolicy-check-in-the-reservation-routine.patch " Andrew Morton
2020-07-28  1:19 ` mmotm 2020-07-27-18-18 uploaded Andrew Morton
     [not found]   ` <ae87385b-f830-dbdf-ebc7-1afb82a7fed0@infradead.org>
2020-07-28 21:55     ` mmotm 2020-07-27-18-18 uploaded (mm/page_alloc.c) Andrew Morton
     [not found]       ` <20200729082053.6c2fb654@canb.auug.org.au>
2020-07-28 22:31         ` Andrew Morton
     [not found]       ` <048cef07-ad4b-8788-94a4-e144de731ab6@infradead.org>
2020-07-29  1:44         ` Andrew Morton
2020-07-28 20:53 ` + mm-mempolicy-fix-kerneldoc-of-numa_map_to_online_node.patch added to -mm tree Andrew Morton
2020-07-28 20:53 ` + mm-mmu_notifier-fix-and-extend-kerneldoc.patch " Andrew Morton
2020-07-28 20:54 ` + mm-swap-fix-kerneldoc-of-swap_vma_readahead.patch " Andrew Morton
2020-07-28 20:58 ` + mm-memcontrol-dont-count-limit-setting-reclaim-as-memory-pressure.patch " Andrew Morton
2020-07-28 21:01 ` + mm-memcontrol-restore-proper-dirty-throttling-when-memoryhigh-changes.patch " Andrew Morton
2020-07-28 22:06 ` + mm-compaction-correct-the-comments-of-compact_defer_shift.patch " Andrew Morton
2020-07-28 22:09 ` + selftests-add-mincore-tests.patch " Andrew Morton
2020-07-28 22:16 ` + proc-pid-smaps-consistent-whitespace-output-format.patch " Andrew Morton
2020-07-28 22:21 ` + xtensa-switch-to-generic-version-of-pte-allocation-fix.patch " Andrew Morton
2020-07-28 22:21 ` Andrew Morton
2020-07-29 21:49 ` + mm-slab-avoid-the-use-of-one-element-array-and-use-struct_size-helper.patch " Andrew Morton
2020-07-29 23:52 ` [obsolete] mm-slab-avoid-the-use-of-one-element-array-and-use-struct_size-helper.patch removed from " Andrew Morton
2020-07-31 19:24 ` + kasan-dont-tag-stacks-allocated-with-pagealloc.patch added to " Andrew Morton
2020-07-31 19:24 ` + kasan-arm64-dont-instrument-functions-that-enable-kasan.patch " Andrew Morton
2020-07-31 19:24 ` + kasan-allow-enabling-stack-tagging-for-tag-based-mode.patch " Andrew Morton
2020-07-31 19:24 ` + kasan-adjust-kasan_stack_oob-for-tag-based-mode.patch " Andrew Morton
2020-07-31 20:00 ` [obsolete] mmhwpoison-rework-soft-offline-for-in-use-pages-fix.patch removed from " Andrew Morton
2020-07-31 20:05 ` + mmhwpoison-cleanup-unused-pagehuge-check.patch added to " Andrew Morton
2020-07-31 20:05 ` + mm-hwpoison-remove-recalculating-hpage.patch " Andrew Morton
2020-07-31 20:05 ` + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch " Andrew Morton
2020-07-31 20:05 ` + mmmadvise-refactor-madvise_inject_error.patch " Andrew Morton
2020-07-31 20:05 ` + mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch " Andrew Morton
2020-07-31 20:05 ` + mmhwpoison-un-export-get_hwpoison_page-and-make-it-static.patch " Andrew Morton
2020-07-31 20:05 ` + mmhwpoison-kill-put_hwpoison_page.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-remove-mf_count_increased.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-remove-flag-argument-from-soft-offline-functions.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-unify-thp-handling-for-hard-and-soft-offline.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-rework-soft-offline-for-free-pages.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-rework-soft-offline-for-in-use-pages.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-refactor-soft_offline_huge_page-and-__soft_offline_page.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-return-0-if-the-page-is-already-poisoned-in-soft-offline.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-introduce-mf_msg_unsplit_thp.patch " Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-double-check-page-count-in-__get_any_page.patch " Andrew Morton
2020-07-31 20:23 ` + mm-gup-restrict-cma-region-by-using-allocation-scope-api.patch " Andrew Morton
2020-07-31 20:23 ` + mm-hugetlb-make-hugetlb-migration-callback-cma-aware.patch " Andrew Morton
2020-07-31 20:23 ` + mm-gup-use-a-standard-migration-target-allocation-callback.patch " Andrew Morton
2020-07-31 20:25 ` + mm-migrate-make-a-standard-migration-target-allocation-function-fix.patch " Andrew Morton
2020-07-31 20:26 ` + mm-memcontrol-decouple-reference-counting-from-page-accounting-fix.patch " Andrew Morton
2020-07-31 20:32 ` + mm-dmapoolc-add-warn_on-in-dma_pool_destroy.patch " Andrew Morton
2020-07-31 20:49 ` + kstrto-correct-documentation-references-to-simple_strto.patch " Andrew Morton
2020-07-31 20:49 ` + kstrto-do-not-describe-simple_strto-as-obsolete-replaced.patch " Andrew Morton
2020-07-31 20:57 ` + mm-hugetlb-fix-calculation-of-adjust_range_if_pmd_sharing_possible.patch " Andrew Morton
2020-07-31 20:59 ` + poison-remove-obsolete-comment.patch " Andrew Morton
2020-07-31 21:02 ` + cma-dont-quit-at-first-error-when-activating-reserved-areas.patch " Andrew Morton
2020-07-31 21:10 ` [nacked] mm-dmapoolc-add-warn_on-in-dma_pool_destroy.patch removed from " Andrew Morton
2020-07-31 23:46 ` mmotm 2020-07-31-16-45 uploaded Andrew Morton

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