The interface is slightly reworked to be more v2 like: - switch from "-1" to "max" for max value following cgroup-v2 style
While on it also: - make oom_guarantee (unsigned long) similar to regular cgroup limits, as we never set more than PAGE_COUNTER_MAX there anyway - set oom_guarantee with xchg(), this ensures that update is atomic https://virtuozzo.atlassian.net/browse/PSBM-154224 Signed-off-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com> Feature: mm/oom: OOM guarantee feature --- v2: - correct commit message part about "max" - make oom_guarantee unsigned long - update oom_guarantee with xchg() --- include/linux/memcontrol.h | 2 +- mm/memcontrol.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 1 deletion(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 9c2b8774639e..2aa330cb81b4 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -263,7 +263,7 @@ struct mem_cgroup { struct vmpressure vmpressure; unsigned long overdraft; - unsigned long long oom_guarantee; + unsigned long oom_guarantee; /* * Should the OOM killer kill all belonging tasks, had it kill one? diff --git a/mm/memcontrol.c b/mm/memcontrol.c index fcc4b24ba330..1722a49855ac 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5239,6 +5239,14 @@ static u64 mem_cgroup_oom_guarantee_read(struct cgroup_subsys_state *css, return mem_cgroup_from_css(css)->oom_guarantee << PAGE_SHIFT; } +static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value); + +static int memory_oom_guarantee_show(struct seq_file *m, void *v) +{ + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->oom_guarantee)); +} + static ssize_t mem_cgroup_oom_guarantee_write(struct kernfs_open_file *kops, char *buffer, size_t nbytes, loff_t off) { @@ -5255,6 +5263,22 @@ static ssize_t mem_cgroup_oom_guarantee_write(struct kernfs_open_file *kops, return nbytes; } +static ssize_t memory_oom_guarantee_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned long oom_guarantee; + int err; + + buf = strstrip(buf); + err = page_counter_memparse(buf, "max", &oom_guarantee); + if (err) + return err; + + xchg(&memcg->oom_guarantee, oom_guarantee); + return nbytes; +} + #ifdef CONFIG_CLEANCACHE static u64 mem_cgroup_disable_cleancache_read(struct cgroup_subsys_state *css, struct cftype *cft) @@ -7629,6 +7653,12 @@ static struct cftype memory_files[] = { .flags = CFTYPE_NS_DELEGATABLE, .write = memory_reclaim, }, + { + .name = "oom_guarantee", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = memory_oom_guarantee_show, + .write = memory_oom_guarantee_write, + }, { } /* terminate */ }; -- 2.43.0 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
