+ memcg-page_alloc-skip-bulk-allocator-for-__gfp_account.patch added to -mm tree

* + memcg-page_alloc-skip-bulk-allocator-for-__gfp_account.patch added to -mm tree
@ 2021-10-13 21:09 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2021-10-13 21:09 UTC (permalink / raw)
  To: guro, hannes, mgorman, mhocko, mm-commits, shakeelb, urezki, vvs


The patch titled
     Subject: memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT
has been added to the -mm tree.  Its filename is
     memcg-page_alloc-skip-bulk-allocator-for-__gfp_account.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/memcg-page_alloc-skip-bulk-allocator-for-__gfp_account.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/memcg-page_alloc-skip-bulk-allocator-for-__gfp_account.patch

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------------------------------------------------------
From: Shakeel Butt <shakeelb@google.com>
Subject: memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT

The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
__vmalloc_area_node()") switched to bulk page allocator for order 0
allocation backing vmalloc.  However bulk page allocator does not support
__GFP_ACCOUNT allocations and there are several users of
kvmalloc(__GFP_ACCOUNT).

For now make __GFP_ACCOUNT allocations bypass bulk page allocator.  In
future if there is workload that can be significantly improved with the
bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
decision.

Link: https://lkml.kernel.org/r/20211013194338.1804247-1-shakeelb@google.com
Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/mm/page_alloc.c~memcg-page_alloc-skip-bulk-allocator-for-__gfp_account
+++ a/mm/page_alloc.c
@@ -5208,6 +5208,10 @@ unsigned long __alloc_pages_bulk(gfp_t g
 	unsigned int alloc_flags = ALLOC_WMARK_LOW;
 	int nr_populated = 0, nr_account = 0;
 
+	/* Bulk allocator does not support memcg accounting. */
+	if (unlikely(gfp & __GFP_ACCOUNT))
+		goto out;
+
 	/*
 	 * Skip populated array elements to determine if any pages need
 	 * to be allocated before disabling IRQs.
_

Patches currently in -mm which might be from shakeelb@google.com are

memcg-flush-stats-only-if-updated.patch
memcg-unify-memcg-stat-flushing.patch
memcg-page_alloc-skip-bulk-allocator-for-__gfp_account.patch


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