The patch titled
Subject: mm: vmpressure: don't count proactive reclaim in vmpressure
has been added to the -mm mm-unstable branch. Its filename is
mm-vmpressure-dont-count-proactive-reclaim-in-vmpressure.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmpressure-dont-count-proactive-reclaim-in-vmpressure.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Subject: mm: vmpressure: don't count proactive reclaim in vmpressure
Date: Thu, 14 Jul 2022 06:49:18 +0000
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.
Link: https://lkml.kernel.org/r/20220714064918.2576464-1-yosryahmed@xxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 5 ++++-
mm/memcontrol.c | 24 ++++++++++++++----------
mm/vmscan.c | 27 +++++++++++++++++----------
3 files changed, 35 insertions(+), 21 deletions(-)
--- a/include/linux/swap.h~mm-vmpressure-dont-count-proactive-reclaim-in-vmpressure
+++ a/include/linux/swap.h
@@ -411,10 +411,13 @@ extern void lru_cache_add_inactive_or_un
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,
--- a/mm/memcontrol.c~mm-vmpressure-dont-count-proactive-reclaim-in-vmpressure
+++ a/mm/memcontrol.c
@@ -2330,7 +2330,8 @@ static unsigned long reclaim_high(struct
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));
@@ -2575,7 +2576,7 @@ static int try_charge_memcg(struct mem_c
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;
bool raised_max_event = false;
unsigned long pflags;
@@ -2593,7 +2594,7 @@ retry:
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) {
@@ -2621,7 +2622,7 @@ retry:
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)
@@ -3439,8 +3440,8 @@ static int mem_cgroup_resize_max(struct
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;
}
@@ -3550,7 +3551,8 @@ static int mem_cgroup_force_empty(struct
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--;
}
@@ -6302,7 +6304,7 @@ static ssize_t memory_high_write(struct
}
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;
@@ -6351,7 +6353,7 @@ static ssize_t memory_max_write(struct k
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;
}
@@ -6480,6 +6482,7 @@ static ssize_t memory_reclaim(struct ker
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);
@@ -6487,6 +6490,7 @@ static ssize_t memory_reclaim(struct ker
if (err)
return err;
+ reclaim_options = MEMCG_RECLAIM_MAY_SWAP | MEMCG_RECLAIM_PROACTIVE;
while (nr_reclaimed < nr_to_reclaim) {
unsigned long reclaimed;
@@ -6503,7 +6507,7 @@ static ssize_t memory_reclaim(struct ker
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;
--- a/mm/vmscan.c~mm-vmpressure-dont-count-proactive-reclaim-in-vmpressure
+++ a/mm/vmscan.c
@@ -101,6 +101,9 @@ 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
@@ -3175,9 +3178,10 @@ static void shrink_node_memcgs(pg_data_t
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)));
}
@@ -3300,9 +3304,10 @@ again:
}
/* 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;
@@ -3584,8 +3589,9 @@ retry:
__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);
@@ -3875,7 +3881,7 @@ unsigned long mem_cgroup_shrink_node(str
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;
@@ -3888,7 +3894,8 @@ unsigned long try_to_free_mem_cgroup_pag
.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
_
Patches currently in -mm which might be from yosryahmed@xxxxxxxxxx are
mm-vmpressure-dont-count-proactive-reclaim-in-vmpressure.patch
