+ mm-apply-per-task-gfp-constraints-in-fast-path.patch added to -mm tree

* + mm-apply-per-task-gfp-constraints-in-fast-path.patch added to -mm tree
@ 2021-02-01 22:59 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2021-02-01 22:59 UTC (permalink / raw)
  To: dan.j.williams, david, iamjoonsoo.kim, ira.weiny, jgg, jgg,
	jhubbard, jmorris, mgorman, mhocko, mhocko, mike.kravetz, mingo,
	mm-commits, osalvador, pasha.tatashin, peterz, rientjes, rostedt,
	sashal, tyhicks, vbabka, willy


The patch titled
     Subject: mm: apply per-task gfp constraints in fast path
has been added to the -mm tree.  Its filename is
     mm-apply-per-task-gfp-constraints-in-fast-path.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-apply-per-task-gfp-constraints-in-fast-path.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-apply-per-task-gfp-constraints-in-fast-path.patch

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there every 3-4 working days

------------------------------------------------------
From: Pavel Tatashin <pasha.tatashin@soleen.com>
Subject: mm: apply per-task gfp constraints in fast path

Function current_gfp_context() is called after fast path.  However, soon
we will add more constraints which will also limit zones based on context.
Move this call into fast path, and apply the correct constraints for all
allocations.

Also update .reclaim_idx based on value returned by current_gfp_context()
because it soon will modify the allowed zones.

Note:
With this patch we will do one extra current->flags load during fast path,
but we already load current->flags in fast-path:

__alloc_pages_nodemask()
 prepare_alloc_pages()
  current_alloc_flags(gfp_mask, *alloc_flags);

Later, when we add the zone constrain logic to current_gfp_context() we
will be able to remove current->flags load from current_alloc_flags, and
therefore return fast-path to the current performance level.

Link: https://lkml.kernel.org/r/20210201153827.444374-7-pasha.tatashin@soleen.com
Suggested-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

--- a/mm/page_alloc.c~mm-apply-per-task-gfp-constraints-in-fast-path
+++ a/mm/page_alloc.c
@@ -4981,6 +4981,13 @@ __alloc_pages_nodemask(gfp_t gfp_mask, u
 	}
 
 	gfp_mask &= gfp_allowed_mask;
+	/*
+	 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
+	 * resp. GFP_NOIO which has to be inherited for all allocation requests
+	 * from a particular context which has been marked by
+	 * memalloc_no{fs,io}_{save,restore}.
+	 */
+	gfp_mask = current_gfp_context(gfp_mask);
 	alloc_mask = gfp_mask;
 	if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
 		return NULL;
@@ -4996,13 +5003,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, u
 	if (likely(page))
 		goto out;
 
-	/*
-	 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
-	 * resp. GFP_NOIO which has to be inherited for all allocation requests
-	 * from a particular context which has been marked by
-	 * memalloc_no{fs,io}_{save,restore}.
-	 */
-	alloc_mask = current_gfp_context(gfp_mask);
+	alloc_mask = gfp_mask;
 	ac.spread_dirty_pages = false;
 
 	/*
_

Patches currently in -mm which might be from pasha.tatashin@soleen.com are

mm-gup-dont-pin-migrated-cma-pages-in-movable-zone.patch
mm-gup-check-every-subpage-of-a-compound-page-during-isolation.patch
mm-gup-return-an-error-on-migration-failure.patch
mm-gup-check-for-isolation-errors.patch
mm-cma-rename-pf_memalloc_nocma-to-pf_memalloc_pin.patch
mm-apply-per-task-gfp-constraints-in-fast-path.patch
mm-honor-pf_memalloc_pin-for-all-movable-pages.patch
mm-gup-do-not-migrate-zero-page.patch
mm-gup-migrate-pinned-pages-out-of-movable-zone.patch
memory-hotplugrst-add-a-note-about-zone_movable-and-page-pinning.patch
mm-gup-change-index-type-to-long-as-it-counts-pages.patch
mm-gup-longterm-pin-migration-cleanup.patch
selftests-vm-gup_test-fix-test-flag.patch
selftests-vm-gup_test-test-faulting-in-kernel-and-verify-pinnable-pages.patch


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