From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752734AbeCWXOj (ORCPT ); Fri, 23 Mar 2018 19:14:39 -0400 Received: from mail-yb0-f193.google.com ([209.85.213.193]:37410 "EHLO mail-yb0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752534AbeCWXNd (ORCPT ); Fri, 23 Mar 2018 19:13:33 -0400 X-Google-Smtp-Source: AG47ELsv9Rti7FAUHDSM1IZ5SdurRSnZe5Vv0igf/Tg1RBQFoQLhvEmI/LnPDxrw5qtrvDRzcziiNA== From: Tejun Heo To: lizefan@huawei.com, hannes@cmpxchg.org Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, guro@fb.com, kernel-team@fb.com, Tejun Heo Subject: [PATCH 5/8] cgroup: Factor out and expose cgroup_rstat_*() interface functions Date: Fri, 23 Mar 2018 16:13:10 -0700 Message-Id: <20180323231313.1254142-6-tj@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20180323231313.1254142-1-tj@kernel.org> References: <20180323231313.1254142-1-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org cgroup_rstat is being generalized so that controllers can use it too. This patch factors out and exposes the following interface functions. * cgroup_rstat_updated(): Renamed from cgroup_rstat_cpu_updated() for consistency. * cgroup_rstat_flush_hold/release(): Factored out from base stat implementation. * cgroup_rstat_flush(): Verbatim expose. While at it, drop assert on cgroup_rstat_mutex in cgroup_base_stat_flush() as it crosses layers and make a minor comment update. Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 11 +++++++++-- kernel/cgroup/cgroup-internal.h | 1 - kernel/cgroup/rstat.c | 41 +++++++++++++++++++++++++++++------------ 3 files changed, 38 insertions(+), 15 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 473e0c0..5c6018f 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -690,11 +690,18 @@ static inline void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, char *buf, size_t buflen) {} #endif /* !CONFIG_CGROUPS */ +#ifdef CONFIG_CGROUPS /* - * Basic resource stats. + * cgroup scalable recursive statistics. */ -#ifdef CONFIG_CGROUPS +void cgroup_rstat_updated(struct cgroup *cgrp, int cpu); +void cgroup_rstat_flush(struct cgroup *cgrp); +void cgroup_rstat_flush_hold(struct cgroup *cgrp); +void cgroup_rstat_flush_release(void); +/* + * Basic resource stats. + */ #ifdef CONFIG_CGROUP_CPUACCT void cpuacct_charge(struct task_struct *tsk, u64 cputime); void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 2bf6fb4..b68e1a7 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -203,7 +203,6 @@ int cgroup_task_count(const struct cgroup *cgrp); /* * rstat.c */ -void cgroup_rstat_flush(struct cgroup *cgrp); int cgroup_rstat_init(struct cgroup *cgrp); void cgroup_rstat_exit(struct cgroup *cgrp); void cgroup_rstat_boot(void); diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index 87d7252..e3c4461 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -13,7 +13,7 @@ static struct cgroup_rstat_cpu *cgroup_rstat_cpu(struct cgroup *cgrp, int cpu) } /** - * cgroup_rstat_cpu_updated - keep track of updated rstat_cpu + * cgroup_rstat_updated - keep track of updated rstat_cpu * @cgrp: target cgroup * @cpu: cpu on which rstat_cpu was updated * @@ -21,7 +21,7 @@ static struct cgroup_rstat_cpu *cgroup_rstat_cpu(struct cgroup *cgrp, int cpu) * rstat_cpu->updated_children list. See the comment on top of * cgroup_rstat_cpu definition for details. */ -static void cgroup_rstat_cpu_updated(struct cgroup *cgrp, int cpu) +void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) { raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); struct cgroup *parent; @@ -167,6 +167,29 @@ void cgroup_rstat_flush(struct cgroup *cgrp) mutex_unlock(&cgroup_rstat_mutex); } +/** + * cgroup_rstat_flush_begin - flush stats in @cgrp's subtree and hold + * @cgrp: target cgroup + * + * Flush stats in @cgrp's subtree and prevent further flushes. Must be + * paired with cgroup_rstat_flush_release(). + */ +void cgroup_rstat_flush_hold(struct cgroup *cgrp) + __acquires(&cgroup_rstat_mutex) +{ + mutex_lock(&cgroup_rstat_mutex); + cgroup_rstat_flush_locked(cgrp); +} + +/** + * cgroup_rstat_flush_release - release cgroup_rstat_flush_hold() + */ +void cgroup_rstat_flush_release(void) + __releases(&cgroup_rstat_mutex) +{ + mutex_unlock(&cgroup_rstat_mutex); +} + int cgroup_rstat_init(struct cgroup *cgrp) { int cpu; @@ -239,15 +262,13 @@ static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) struct cgroup_base_stat delta; unsigned seq; - lockdep_assert_held(&cgroup_rstat_mutex); - /* fetch the current per-cpu values */ do { seq = __u64_stats_fetch_begin(&rstatc->bsync); cputime = rstatc->bstat.cputime; } while (__u64_stats_fetch_retry(&rstatc->bsync, seq)); - /* accumulate the deltas to propgate */ + /* calculate the delta to propgate */ delta.cputime.utime = cputime.utime - last_cputime->utime; delta.cputime.stime = cputime.stime - last_cputime->stime; delta.cputime.sum_exec_runtime = cputime.sum_exec_runtime - @@ -278,7 +299,7 @@ static void cgroup_base_stat_cputime_account_end(struct cgroup *cgrp, struct cgroup_rstat_cpu *rstatc) { u64_stats_update_end(&rstatc->bsync); - cgroup_rstat_cpu_updated(cgrp, smp_processor_id()); + cgroup_rstat_updated(cgrp, smp_processor_id()); put_cpu_ptr(rstatc); } @@ -323,14 +344,10 @@ void cgroup_base_stat_cputime_show(struct seq_file *seq) if (!cgroup_parent(cgrp)) return; - mutex_lock(&cgroup_rstat_mutex); - - cgroup_rstat_flush_locked(cgrp); - + cgroup_rstat_flush_hold(cgrp); usage = cgrp->bstat.cputime.sum_exec_runtime; cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime, &utime, &stime); - - mutex_unlock(&cgroup_rstat_mutex); + cgroup_rstat_flush_release(); do_div(usage, NSEC_PER_USEC); do_div(utime, NSEC_PER_USEC); -- 2.9.5