[RFC,1/1] delayacct: add memory reclaim delay in

Commit Message

[e-mail] Aug. 23, 2023, 6:28 a.m. UTC

The current memory reclaim delay statistics only count the direct memory
reclaim of the task under slow memory allocation. In systems with NUMA
open, some tasks occasionally experience slower response times, but the
total count of reclaim does not increase, using ftrace can show that
node_reclaim has occurred.

the memory reclaim under get_page_from_freelist() is also due to heavy
memory load. To get the impact of tasks in memory reclaim, this patch adds
the statistics of the memory reclaim delay statistics for __node_reclaim().

Signed-off-by: Wen Yu Li <[e-mail]>
---
 mm/vmscan.c | 2 ++
 1 file changed, 2 insertions(+)

--
2.30.2



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Patch

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1080209a568b..d2471abce1ae 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -8010,6 +8010,7 @@  static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in

        cond_resched();
        psi_memstall_enter(&pflags);
+       delayacct_freepages_start();
        fs_reclaim_acquire(sc.gfp_mask);
        /*
         * We need to be able to allocate from the reserves for RECLAIM_UNMAP
@@ -8032,6 +8033,7 @@  static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in
        memalloc_noreclaim_restore(noreclaim_flag);
        fs_reclaim_release(sc.gfp_mask);
        psi_memstall_leave(&pflags);
+       delayacct_freepages_end();

        trace_mm_vmscan_node_reclaim_end(sc.nr_reclaimed);