The patch titled
Subject: mm: memcg: remove unneeded checks from newpage_charge()
has been added to the -mm tree. Its filename is
mm-memcg-remove-unneeded-checks-from-newpage_charge.patch
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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/
------------------------------------------------------
From: Johannes Weiner <jweiner@xxxxxxxxxx>
Subject: mm: memcg: remove unneeded checks from newpage_charge()
All callsites pass in freshly allocated pages and a valid mm. As a
result, all checks pertaining to the page's mapcount, page->mapping or the
fallback to init_mm are unneeded.
Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff -puN mm/memcontrol.c~mm-memcg-remove-unneeded-checks-from-newpage_charge mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcg-remove-unneeded-checks-from-newpage_charge
+++ a/mm/memcontrol.c
@@ -2679,19 +2679,11 @@ int mem_cgroup_newpage_charge(struct pag
{
if (mem_cgroup_disabled())
return 0;
- /*
- * If already mapped, we don't have to account.
- * If page cache, page->mapping has address_space.
- * But page->mapping may have out-of-use anon_vma pointer,
- * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
- * is NULL.
- */
- if (page_mapped(page) || (page->mapping && !PageAnon(page)))
- return 0;
- if (unlikely(!mm))
- mm = &init_mm;
+ VM_BUG_ON(page_mapped(page));
+ VM_BUG_ON(page->mapping && !PageAnon(page));
+ VM_BUG_ON(!mm);
return mem_cgroup_charge_common(page, mm, gfp_mask,
- MEM_CGROUP_CHARGE_TYPE_MAPPED);
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
}
static void
_
Subject: Subject: mm: memcg: remove unneeded checks from newpage_charge()
Patches currently in -mm which might be from jweiner@xxxxxxxxxx are
mm-add-extra-free-kbytes-tunable.patch
mm-migrate-one-less-atomic-operation.patch
hugetlb-detect-race-upon-page-allocation-failure-during-cow.patch
hugetlb-clarify-hugetlb_instantiation_mutex-usage.patch
fadvise-only-initiate-writeback-for-specified-range-with-fadv_dontneed.patch
mm-exclude-reserved-pages-from-dirtyable-memory.patch
mm-exclude-reserved-pages-from-dirtyable-memory-fix.patch
mm-writeback-cleanups-in-preparation-for-per-zone-dirty-limits.patch
mm-try-to-distribute-dirty-pages-fairly-across-zones.patch
mm-filemap-pass-__gfp_write-from-grab_cache_page_write_begin.patch
btrfs-pass-__gfp_write-for-buffered-write-page-allocations.patch
mm-memcg-consolidate-hierarchy-iteration-primitives.patch
mm-vmscan-distinguish-global-reclaim-from-global-lru-scanning.patch
mm-vmscan-distinguish-between-memcg-triggering-reclaim-and-memcg-being-scanned.patch
mm-vmscan-distinguish-between-memcg-triggering-reclaim-and-memcg-being-scanned-checkpatch-fixes.patch
mm-memcg-per-priority-per-zone-hierarchy-scan-generations.patch
mm-move-memcg-hierarchy-reclaim-to-generic-reclaim-code.patch
mm-memcg-remove-optimization-of-keeping-the-root_mem_cgroup-lru-lists-empty.patch
mm-vmscan-convert-global-reclaim-to-per-memcg-lru-lists.patch
mm-collect-lru-list-heads-into-struct-lruvec.patch
mm-make-per-memcg-lru-lists-exclusive.patch
mm-memcg-remove-unused-node-section-info-from-pc-flags.patch
mm-memcg-remove-unused-node-section-info-from-pc-flags-fix.patch
mm-memcg-shorten-preempt-disabled-section-around-event-checks.patch
mm-oom_kill-remove-memcg-argument-from-oom_kill_task.patch
mm-unify-remaining-mem_cont-mem-etc-variable-names-to-memcg.patch
mm-memcg-clean-up-fault-accounting.patch
mm-memcg-lookup_page_cgroup-almost-never-returns-null.patch
mm-memcg-remove-unneeded-checks-from-newpage_charge.patch
mm-memcg-remove-unneeded-checks-from-uncharge_page.patch
thp-improve-the-error-code-path.patch
thp-remove-unnecessary-tlb-flush-for-mprotect.patch
thp-add-tlb_remove_pmd_tlb_entry.patch
thp-improve-order-in-lru-list-for-split-huge-page.patch
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