From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + ksm-mem-cgroup-charge-swapin-copy.patch added to -mm tree Date: Tue, 24 Nov 2009 11:35:38 -0800 Message-ID: <200911241935.nAOJZcSC028474@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:56780 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758197AbZKXTft (ORCPT ); Tue, 24 Nov 2009 14:35:49 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: hugh.dickins@tiscali.co.uk, aarcange@redhat.com, chrisw@redhat.com, ieidus@redhat.com The patch titled ksm: mem cgroup charge swapin copy has been added to the -mm tree. Its filename is ksm-mem-cgroup-charge-swapin-copy.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ksm: mem cgroup charge swapin copy From: Hugh Dickins But ksm swapping does require one small change in mem cgroup handling. When do_swap_page()'s call to ksm_might_need_to_copy() does indeed substitute a duplicate page to accommodate a different anon_vma (or a the !PageSwapCache check in mem_cgroup_try_charge_swapin(). That was returning success without charging, on the assumption that pte_same() would fail after, which is not the case here. Originally I proposed that success, so that an unshrinkable mem cgroup at its limit would not fail unnecessarily; but that's a minor point, and there are plenty of other places where we may fail an overallocation which might later prove unnecessary. So just go ahead and do what all the other exceptions do: proceed to charge current mm. Signed-off-by: Hugh Dickins Cc: Izik Eidus Cc: Andrea Arcangeli Cc: Chris Wright Signed-off-by: Andrew Morton --- mm/memcontrol.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff -puN mm/memcontrol.c~ksm-mem-cgroup-charge-swapin-copy mm/memcontrol.c --- a/mm/memcontrol.c~ksm-mem-cgroup-charge-swapin-copy +++ a/mm/memcontrol.c @@ -1737,11 +1737,12 @@ int mem_cgroup_try_charge_swapin(struct goto charge_cur_mm; /* * A racing thread's fault, or swapoff, may have already updated - * the pte, and even removed page from swap cache: return success - * to go on to do_swap_page()'s pte_same() test, which should fail. + * the pte, and even removed page from swap cache: in those cases + * do_swap_page()'s pte_same() test will fail; but there's also a + * KSM case which does need to charge the page. */ if (!PageSwapCache(page)) - return 0; + goto charge_cur_mm; mem = try_get_mem_cgroup_from_swapcache(page); if (!mem) goto charge_cur_mm; _ Patches currently in -mm which might be from hugh.dickins@tiscali.co.uk are mmap-dont-return-enomem-when-mapcount-is-temporarily-exceeded-in-munmap.patch mmap-dont-return-enomem-when-mapcount-is-temporarily-exceeded-in-munmap-checkpatch-fixes.patch vmalloc-adjust-gfp-mask-passed-on-nested-vmalloc-invocation.patch swap_info-private-to-swapfilec.patch swap_info-change-to-array-of-pointers.patch swap_info-include-first_swap_extent.patch swap_info-include-first_swap_extent-fix.patch swap_info-include-first_swap_extent-fix-fix.patch swap_info-miscellaneous-minor-cleanups.patch swap_info-swap_has_cache-cleanups.patch swap_info-swap_map-of-chars-not-shorts.patch swap_info-swap-count-continuations.patch swap_info-note-swap_map_shmem.patch swap_info-reorder-its-fields.patch rmap-fix-the-comment-for-try_to_unmap_anon.patch oom_kill-use-rss-value-instead-of-vm-size-for-badness.patch mm-define-page_mapping_flags.patch mm-mlocking-in-try_to_unmap_one.patch mm-mlocking-in-try_to_unmap_one-fix.patch mm-mlocking-in-try_to_unmap_one-fix-fix.patch mm-config_mmu-for-pg_mlocked.patch mm-pass-address-down-to-rmap-ones.patch mm-stop-ptlock-enlarging-struct-page.patch mm-sigbus-instead-of-abusing-oom.patch ksm-three-remove_rmap_item_from_tree-cleanups.patch ksm-remove-redundancies-when-merging-page.patch ksm-cleanup-some-function-arguments.patch ksm-singly-linked-rmap_list.patch ksm-separate-stable_node.patch ksm-stable_node-point-to-page-and-back.patch ksm-fix-mlockfreed-to-munlocked.patch ksm-let-shared-pages-be-swappable.patch ksm-hold-anon_vma-in-rmap_item.patch ksm-take-keyhole-reference-to-page.patch ksm-share-anon-page-without-allocating.patch ksm-mem-cgroup-charge-swapin-copy.patch ksm-rmap_walk-to-remove_migation_ptes.patch ksm-memory-hotremove-migration-only.patch ksm-remove-unswappable-max_kernel_pages.patch hugetlb-prevent-deadlock-in-__unmap_hugepage_range-when-alloc_huge_page-fails-2.patch mm-simplify-try_to_unmap_one.patch mm-simplify-try_to_unmap_one-fix.patch elf-kill-use_elf_core_dump.patch prio_tree-debugging-patch.patch