| Message ID | bbec2c3d822217334855c8877a9d28b2a6d395fb.1584034301.git.chris@chrisdown.name (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm, memcg: cgroup v2 tunable load/store tearing fixes | expand |
On Thu 12-03-20 17:33:11, Chris Down wrote: > The write side of this is xchg()/smp_mb(), so that's all good. Just a > few sites missing a READ_ONCE. > > Signed-off-by: Chris Down <chris@chrisdown.name> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Roman Gushchin <guro@fb.com> > Cc: Tejun Heo <tj@kernel.org> > Cc: linux-mm@kvack.org > Cc: cgroups@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: kernel-team@fb.com Acked-by: Michal Hocko <mhocko@suse.com> > --- > mm/memcontrol.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index e0ed790a2a8c..57048a38c75d 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1511,7 +1511,7 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) > if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) > pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", > K((u64)page_counter_read(&memcg->swap)), > - K((u64)memcg->swap.max), memcg->swap.failcnt); > + K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); > else { > pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", > K((u64)page_counter_read(&memcg->memsw)), > @@ -1544,7 +1544,7 @@ unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) > unsigned long swap_max; > > memsw_max = memcg->memsw.max; > - swap_max = memcg->swap.max; > + swap_max = READ_ONCE(memcg->swap.max); > swap_max = min(swap_max, (unsigned long)total_swap_pages); > max = min(max + swap_max, memsw_max); > } > @@ -7025,7 +7025,8 @@ bool mem_cgroup_swap_full(struct page *page) > return false; > > for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) > - if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.max) > + if (page_counter_read(&memcg->swap) * 2 >= > + READ_ONCE(memcg->swap.max)) > return true; > > return false; > -- > 2.25.1 >
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e0ed790a2a8c..57048a38c75d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1511,7 +1511,7 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->swap)), - K((u64)memcg->swap.max), memcg->swap.failcnt); + K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); else { pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->memsw)), @@ -1544,7 +1544,7 @@ unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) unsigned long swap_max; memsw_max = memcg->memsw.max; - swap_max = memcg->swap.max; + swap_max = READ_ONCE(memcg->swap.max); swap_max = min(swap_max, (unsigned long)total_swap_pages); max = min(max + swap_max, memsw_max); } @@ -7025,7 +7025,8 @@ bool mem_cgroup_swap_full(struct page *page) return false; for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) - if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.max) + if (page_counter_read(&memcg->swap) * 2 >= + READ_ONCE(memcg->swap.max)) return true; return false;
The write side of this is xchg()/smp_mb(), so that's all good. Just a few sites missing a READ_ONCE. Signed-off-by: Chris Down <chris@chrisdown.name> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: linux-mm@kvack.org Cc: cgroups@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: kernel-team@fb.com --- mm/memcontrol.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)