From: Johannes Weiner <hannes@cmpxchg.org> mainline inclusion from mainline-5.14-rc7 commit 57f29762cdd4687a02f245d1b1e78de046388eac category: bugfix bugzilla: 176927 https://gitee.com/openeuler/kernel/issues/I4DDEL Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------ 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> Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Reviewed-by: Chen Wandun <chenwandun@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- mm/vmscan.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/vmscan.c b/mm/vmscan.c index f5d3f920b462..2ff583edd2f8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4393,11 +4393,13 @@ 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 @@ -4422,6 +4424,7 @@ 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); -- 2.20.1