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dkim=pass header.d=google.com header.s=20210112 header.b=O5iei60W; spf=pass (imf21.hostedemail.com: domain of yosryahmed@google.com designates 209.85.221.46 as permitted sender) smtp.mailfrom=yosryahmed@google.com; dmarc=pass (policy=reject) header.from=google.com X-Stat-Signature: tn14nomqu8kwxcu46toh88dn65ecocit X-Rspamd-Server: rspam07 X-HE-Tag: 1658251989-603401 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jul 13, 2022 at 11:49 PM Yosry Ahmed wrote: > > vmpressure is used in cgroup v1 to notify userspace of reclaim > efficiency events, and is also used in both cgroup v1 and v2 as a signal > for memory pressure for networking, see > mem_cgroup_under_socket_pressure(). > > Proactive reclaim intends to probe memcgs for cold memory, without > affecting their performance. Hence, reclaim caused by writing to > memory.reclaim should not trigger vmpressure. > > Signed-off-by: Yosry Ahmed > Acked-by: Shakeel Butt > --- > Changes in v4: > - Removed unneeded reclaim_options local variables (Andrew). > > Changes in v3: > - Limited the vmpressure change to memory.reclaim, dropped psi changes, > updated changelog to reflect new behavior (Michal, Shakeel) > > Changes in v2: > - Removed unnecessary initializations to zero (Andrew). > - Separate declarations and initializations when it causes line wrapping > (Andrew). > > --- > include/linux/swap.h | 5 ++++- > mm/memcontrol.c | 24 ++++++++++++++---------- > mm/vmscan.c | 27 +++++++++++++++++---------- > 3 files changed, 35 insertions(+), 21 deletions(-) > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index 0c0fed1b348f..f6e9eaa2339f 100644 > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -411,10 +411,13 @@ extern void lru_cache_add_inactive_or_unevictable(struct page *page, > extern unsigned long zone_reclaimable_pages(struct zone *zone); > extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, > gfp_t gfp_mask, nodemask_t *mask); > + > +#define MEMCG_RECLAIM_MAY_SWAP (1 << 1) > +#define MEMCG_RECLAIM_PROACTIVE (1 << 2) > extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, > unsigned long nr_pages, > gfp_t gfp_mask, > - bool may_swap); > + unsigned int reclaim_options); > extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, > gfp_t gfp_mask, bool noswap, > pg_data_t *pgdat, > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index a550042d88c3..b668224142c7 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2331,7 +2331,8 @@ static unsigned long reclaim_high(struct mem_cgroup *memcg, > > psi_memstall_enter(&pflags); > nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, > - gfp_mask, true); > + gfp_mask, > + MEMCG_RECLAIM_MAY_SWAP); > psi_memstall_leave(&pflags); > } while ((memcg = parent_mem_cgroup(memcg)) && > !mem_cgroup_is_root(memcg)); > @@ -2576,7 +2577,7 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, > struct page_counter *counter; > unsigned long nr_reclaimed; > bool passed_oom = false; > - bool may_swap = true; > + unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP; > bool drained = false; > unsigned long pflags; > > @@ -2593,7 +2594,7 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, > mem_over_limit = mem_cgroup_from_counter(counter, memory); > } else { > mem_over_limit = mem_cgroup_from_counter(counter, memsw); > - may_swap = false; > + reclaim_options &= ~MEMCG_RECLAIM_MAY_SWAP; > } > > if (batch > nr_pages) { > @@ -2620,7 +2621,7 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, > > psi_memstall_enter(&pflags); > nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, > - gfp_mask, may_swap); > + gfp_mask, reclaim_options); > psi_memstall_leave(&pflags); > > if (mem_cgroup_margin(mem_over_limit) >= nr_pages) > @@ -3402,8 +3403,8 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg, > continue; > } > > - if (!try_to_free_mem_cgroup_pages(memcg, 1, > - GFP_KERNEL, !memsw)) { > + if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, > + memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP)) { > ret = -EBUSY; > break; > } > @@ -3513,7 +3514,8 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) > if (signal_pending(current)) > return -EINTR; > > - if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true)) > + if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, > + MEMCG_RECLAIM_MAY_SWAP)) > nr_retries--; > } > > @@ -6248,7 +6250,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, > } > > reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, > - GFP_KERNEL, true); > + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP); > > if (!reclaimed && !nr_retries--) > break; > @@ -6297,7 +6299,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, > > if (nr_reclaims) { > if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, > - GFP_KERNEL, true)) > + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP)) > nr_reclaims--; > continue; > } > @@ -6426,6 +6428,7 @@ static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, > struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); > unsigned int nr_retries = MAX_RECLAIM_RETRIES; > unsigned long nr_to_reclaim, nr_reclaimed = 0; > + unsigned int reclaim_options; > int err; > > buf = strstrip(buf); > @@ -6433,6 +6436,7 @@ static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, > if (err) > return err; > > + reclaim_options = MEMCG_RECLAIM_MAY_SWAP | MEMCG_RECLAIM_PROACTIVE; > while (nr_reclaimed < nr_to_reclaim) { > unsigned long reclaimed; > > @@ -6449,7 +6453,7 @@ static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, > > reclaimed = try_to_free_mem_cgroup_pages(memcg, > nr_to_reclaim - nr_reclaimed, > - GFP_KERNEL, true); > + GFP_KERNEL, reclaim_options); > > if (!reclaimed && !nr_retries--) > return -EAGAIN; > diff --git a/mm/vmscan.c b/mm/vmscan.c > index f7d9a683e3a7..0969e6408a53 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -102,6 +102,9 @@ struct scan_control { > /* Can pages be swapped as part of reclaim? */ > unsigned int may_swap:1; > > + /* Proactive reclaim invoked by userspace through memory.reclaim */ > + unsigned int proactive:1; > + > /* > * Cgroup memory below memory.low is protected as long as we > * don't threaten to OOM. If any cgroup is reclaimed at > @@ -3125,9 +3128,10 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc) > sc->priority); > > /* Record the group's reclaim efficiency */ > - vmpressure(sc->gfp_mask, memcg, false, > - sc->nr_scanned - scanned, > - sc->nr_reclaimed - reclaimed); > + if (!sc->proactive) > + vmpressure(sc->gfp_mask, memcg, false, > + sc->nr_scanned - scanned, > + sc->nr_reclaimed - reclaimed); > > } while ((memcg = mem_cgroup_iter(target_memcg, memcg, NULL))); > } > @@ -3250,9 +3254,10 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) > } > > /* Record the subtree's reclaim efficiency */ > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, true, > - sc->nr_scanned - nr_scanned, > - sc->nr_reclaimed - nr_reclaimed); > + if (!sc->proactive) > + vmpressure(sc->gfp_mask, sc->target_mem_cgroup, true, > + sc->nr_scanned - nr_scanned, > + sc->nr_reclaimed - nr_reclaimed); > > if (sc->nr_reclaimed - nr_reclaimed) > reclaimable = true; > @@ -3534,8 +3539,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, > __count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1); > > do { > - vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup, > - sc->priority); > + if (!sc->proactive) > + vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup, > + sc->priority); > sc->nr_scanned = 0; > shrink_zones(zonelist, sc); > > @@ -3825,7 +3831,7 @@ unsigned long mem_cgroup_shrink_node(struct mem_cgroup *memcg, > unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, > unsigned long nr_pages, > gfp_t gfp_mask, > - bool may_swap) > + unsigned int reclaim_options) > { > unsigned long nr_reclaimed; > unsigned int noreclaim_flag; > @@ -3838,7 +3844,8 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, > .priority = DEF_PRIORITY, > .may_writepage = !laptop_mode, > .may_unmap = 1, > - .may_swap = may_swap, > + .may_swap = !!(reclaim_options & MEMCG_RECLAIM_MAY_SWAP), > + .proactive = !!(reclaim_options & MEMCG_RECLAIM_PROACTIVE), > }; > /* > * Traverse the ZONELIST_FALLBACK zonelist of the current node to put > -- > 2.37.0.144.g8ac04bfd2-goog > Hey Michal, Any outstanding comments/thoughts on this version?