From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, hannes@cmpxchg.org,
linux-mm@kvack.org, mm-commits@vger.kernel.org, riel@surriel.com,
shakeelb@google.com, torvalds@linux-foundation.org
Subject: [patch 08/10] mm: vmscan: fix missing psi annotation for node_reclaim()
Date: Thu, 19 Aug 2021 19:04:27 -0700 [thread overview]
Message-ID: <20210820020427.f6efFx9EV%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210819190327.14fc4e97102e1af7929e30af@linux-foundation.org>
From: Johannes Weiner <hannes@cmpxchg.org>
Subject: mm: vmscan: fix missing psi annotation for node_reclaim()
In a debugging session the other day, Rik noticed that node_reclaim() was
missing memstall annotations. This means we'll miss pressure and lost
productivity resulting from reclaim on an overloaded local NUMA node when
vm.zone_reclaim_mode is enabled.
There haven't been any reports, but that's likely because
vm.zone_reclaim_mode hasn't been a commonly used feature recently, and the
intersection between such setups and psi users is probably nil. Although,
secondary memory such as CXL-connected DIMMS, persistent memory etc. and
the page demotion patches that handle them
(https://lore.kernel.org/lkml/20210401183216.443C4443@viggo.jf.intel.com/)
could soon make this a more common codepath again.
Link: https://lkml.kernel.org/r/20210818152457.35846-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/vmscan.c | 3 +++
1 file changed, 3 insertions(+)
--- a/mm/vmscan.c~mm-vmscan-fix-missing-psi-annotation-for-node_reclaim
+++ a/mm/vmscan.c
@@ -4424,11 +4424,13 @@ static int __node_reclaim(struct pglist_
.may_swap = 1,
.reclaim_idx = gfp_zone(gfp_mask),
};
+ unsigned long pflags;
trace_mm_vmscan_node_reclaim_begin(pgdat->node_id, order,
sc.gfp_mask);
cond_resched();
+ psi_memstall_enter(&pflags);
fs_reclaim_acquire(sc.gfp_mask);
/*
* We need to be able to allocate from the reserves for RECLAIM_UNMAP
@@ -4453,6 +4455,7 @@ static int __node_reclaim(struct pglist_
current->flags &= ~PF_SWAPWRITE;
memalloc_noreclaim_restore(noreclaim_flag);
fs_reclaim_release(sc.gfp_mask);
+ psi_memstall_leave(&pflags);
trace_mm_vmscan_node_reclaim_end(sc.nr_reclaimed);
_
next prev parent reply other threads:[~2021-08-20 2:04 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 2:03 incoming Andrew Morton
2021-08-20 2:04 ` [patch 01/10] Revert "mm/shmem: fix shmem_swapin() race with swapoff" Andrew Morton
2021-08-20 2:04 ` [patch 02/10] Revert "mm: swap: check if swap backing device is congested or not" Andrew Morton
2021-08-20 2:04 ` [patch 03/10] mm/page_alloc: don't corrupt pcppage_migratetype Andrew Morton
2021-08-20 2:04 ` [patch 04/10] mmflags.h: add missing __GFP_ZEROTAGS and __GFP_SKIP_KASAN_POISON names Andrew Morton
2021-08-20 2:04 ` [patch 05/10] MAINTAINERS: update ClangBuiltLinux IRC chat Andrew Morton
2021-08-20 2:04 ` [patch 06/10] mm: memcontrol: fix occasional OOMs due to proportional memory.low reclaim Andrew Morton
2021-08-20 2:04 ` [patch 07/10] mm/hwpoison: retry with shake_page() for unhandlable pages Andrew Morton
2021-08-20 2:04 ` Andrew Morton [this message]
2021-08-20 2:04 ` [patch 09/10] kfence: fix is_kfence_address() for addresses below KFENCE_POOL_SIZE Andrew Morton
2021-08-20 2:04 ` [patch 10/10] hugetlb: don't pass page cache pages to restore_reserve_on_error Andrew Morton
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