On Thu, 31 Aug 2023 07:26:20 +0000 "liwenyu01@xxxxxxxxxxxx" <liwenyu01@xxxxxxxxxxxx> wrote: > reclaim of the task in do_try_to_free_pages(). 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 occurring in 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(). > > ... > > --- 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); __node_reclaim() calls shrink_node() which at some point will call do_try_to_free_pages() (yes?), which calls delayacct_freepages_start(). So we're effectively nesting calls to delayacct_freepages_start(), which isn't designed for that?
