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| author | Johannes Weiner <hannes@cmpxchg.org> | 2021-08-19 19:04:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-20 11:31:42 -0700 |
| commit | 57f29762cdd4687a02f245d1b1e78de046388eac (patch) | |
| tree | 618d4ae22167aef73c1cb0cd605ff244fcd43326 | |
| parent | fcc00621d88b274b5dffd8daeea71d0e4c28b84e (diff) | |
| download | linux-57f29762cdd4687a02f245d1b1e78de046388eac.tar.gz | |
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.
But 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/vmscan.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index b0202ab5e1360a..eeae2f6bc53203 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4424,11 +4424,13 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in .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_data *pgdat, gfp_t gfp_mask, unsigned in 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); |