Create a new function of_peak_reset that resets the page_counter peak for a given writer. This should allow it to be reused by other cgroups.
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]> --- include/linux/cgroup-defs.h | 6 ++++++ kernel/cgroup/cgroup.c | 32 ++++++++++++++++++++++++++++++++ mm/memcontrol.c | 42 ++++++++---------------------------------- 3 files changed, 46 insertions(+), 34 deletions(-) diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index f42563739d2e..a85044cb0553 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -22,6 +22,7 @@ #include <linux/workqueue.h> #include <linux/bpf-cgroup-defs.h> #include <linux/psi_types.h> +#include <linux/page_counter.h> #ifdef CONFIG_CGROUPS @@ -868,11 +869,16 @@ struct cgroup_subsys { extern struct percpu_rw_semaphore cgroup_threadgroup_rwsem; extern bool cgroup_enable_per_threadgroup_rwsem; +#define OFP_PEAK_UNSET (((-1UL))) + struct cgroup_of_peak { unsigned long value; struct list_head list; }; +void of_peak_reset(struct cgroup_of_peak *ofp, struct page_counter *pc, + struct list_head *watchers); + /** * cgroup_threadgroup_change_begin - threadgroup exclusion for cgroups * @tsk: target task diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 45c0b1ed687a..9b98a5cccf0e 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1981,6 +1981,38 @@ struct cgroup_of_peak *of_peak(struct kernfs_open_file *of) return &ctx->peak; } +/** + * of_peak_reset - reset peak + * @ofp: open file context + * @pc: counter + * @watchers: list of other open file contexts + * + * This function updates all contexts in @watchers to the new usage of @pc. + * If @ofp is not in the list yet, that is, if its value is + * %OFP_PEAK_UNSET, it is added to @watchers list. + * + * A lock must be used to protect @watchers. + */ +void of_peak_reset(struct cgroup_of_peak *ofp, struct page_counter *pc, + struct list_head *watchers) +{ + unsigned long usage; + struct cgroup_of_peak *peer_ctx; + + usage = page_counter_read(pc); + WRITE_ONCE(pc->local_watermark, usage); + + list_for_each_entry(peer_ctx, watchers, list) + if (usage > peer_ctx->value) + WRITE_ONCE(peer_ctx->value, usage); + + /* initial write, register watcher */ + if (ofp->value == OFP_PEAK_UNSET) + list_add(&ofp->list, watchers); + + WRITE_ONCE(ofp->value, usage); +} + static void apply_cgroup_root_flags(unsigned int root_flags) { if (current->nsproxy->cgroup_ns == &init_cgroup_ns) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c03d4787d466..8754927070d3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4517,8 +4517,6 @@ static u64 memory_current_read(struct cgroup_subsys_state *css, return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; } -#define OFP_PEAK_UNSET (((-1UL))) - static int peak_show(struct seq_file *sf, void *v, struct page_counter *pc) { struct cgroup_of_peak *ofp = of_peak(sf->private); @@ -4563,45 +4561,18 @@ static void peak_release(struct kernfs_open_file *of) spin_unlock(&memcg->peaks_lock); } -static ssize_t peak_write(struct kernfs_open_file *of, char *buf, size_t nbytes, - loff_t off, struct page_counter *pc, - struct list_head *watchers) +static ssize_t memory_peak_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) { - unsigned long usage; - struct cgroup_of_peak *peer_ctx; struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); struct cgroup_of_peak *ofp = of_peak(of); spin_lock(&memcg->peaks_lock); - - usage = page_counter_read(pc); - WRITE_ONCE(pc->local_watermark, usage); - - list_for_each_entry(peer_ctx, watchers, list) - if (usage > peer_ctx->value) - WRITE_ONCE(peer_ctx->value, usage); - - /* initial write, register watcher */ - if (ofp->value == OFP_PEAK_UNSET) - list_add(&ofp->list, watchers); - - WRITE_ONCE(ofp->value, usage); + of_peak_reset(ofp, &memcg->memory, &memcg->memory_peaks); spin_unlock(&memcg->peaks_lock); - return nbytes; } -static ssize_t memory_peak_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)); - - return peak_write(of, buf, nbytes, off, &memcg->memory, - &memcg->memory_peaks); -} - -#undef OFP_PEAK_UNSET - static int memory_min_show(struct seq_file *m, void *v) { return seq_puts_memcg_tunable(m, @@ -5611,9 +5582,12 @@ static ssize_t swap_peak_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)); + struct cgroup_of_peak *ofp = of_peak(of); - return peak_write(of, buf, nbytes, off, &memcg->swap, - &memcg->swap_peaks); + spin_lock(&memcg->peaks_lock); + of_peak_reset(ofp, &memcg->swap, &memcg->swap_peaks); + spin_unlock(&memcg->peaks_lock); + return nbytes; } static int swap_high_show(struct seq_file *m, void *v) -- 2.47.3
