From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 908DB235046 for ; Wed, 21 May 2025 16:57:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747846664; cv=none; b=jD0FPaEGkcphVJoF3jgtP2RyLbIH233sNlDGlCQt9X23XcBLad0hd0lk95xC8+JgyhT2rE2hgfOX62UcBo/C36CqihrPWIbskV6PJTXDTaoHl6eVSkzYkY8DWI51z8c14mvxGXmJkLibBd30yqjXFXXCDWRk9yJV8RVu80PeBZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747846664; c=relaxed/simple; bh=hvsfVgMnebxuPsbazutH0ORFlLHwM10Id72gWkR3O/s=; h=Date:To:From:Subject:Message-Id; b=sGEY/l9uKGZC8+KkmVt4mlBJW4ujtzxGwP+filFwfqTTdUSTiCWohuR7J7wSxnCBIBSy/gNC28uwGLfAso7OC0zrK8nSOptwiw0nl2M5ivbQ/yeGbZuSFn2L+/eMEcrWg1IGMQTRzOxPswWsOx/LlR/AEWPTBEe8dfL49ufPxsA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=lz8az8Xr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="lz8az8Xr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64888C4CEE4; Wed, 21 May 2025 16:57:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1747846664; bh=hvsfVgMnebxuPsbazutH0ORFlLHwM10Id72gWkR3O/s=; h=Date:To:From:Subject:From; b=lz8az8XrZE19qeIAMlOKJjQqqODyYIrqL5I1hs2Lxx1HbHUe9H6PXjBRTVOT6H6cH 1z80YuTpCxYjS611y7WHmSEjgMjAwb9v/JQ/mGoaed5w4kF93Xy7tIh815vojvE+gh sVYpUTrVzm6nIzVOVTCPOOcZpotYSEHJixX7GR9U= Date: Wed, 21 May 2025 09:57:43 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,roman.gushchin@linux.dev,muchun.song@linux.dev,mhocko@kernel.org,hannes@cmpxchg.org,bigeasy@linutronix.de,ast@kernel.org,shakeel.butt@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] memcg-move-preempt-disable-to-callers-of-memcg_rstat_updated.patch removed from -mm tree Message-Id: <20250521165744.64888C4CEE4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: memcg: move preempt disable to callers of memcg_rstat_updated has been removed from the -mm tree. Its filename was memcg-move-preempt-disable-to-callers-of-memcg_rstat_updated.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Shakeel Butt Subject: memcg: move preempt disable to callers of memcg_rstat_updated Date: Wed, 14 May 2025 11:41:53 -0700 Let's move the explicit preempt disable code to the callers of memcg_rstat_updated and also remove the memcg_stats_lock and related functions which ensures the callers of stats update functions have disabled preemption because now the stats update functions are explicitly disabling preemption. Link: https://lkml.kernel.org/r/20250514184158.3471331-3-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt Acked-by: Vlastimil Babka Cc: Alexei Starovoitov Cc: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin Cc: Sebastian Andrzej Siewior Signed-off-by: Andrew Morton --- mm/memcontrol.c | 74 +++++++++++----------------------------------- 1 file changed, 19 insertions(+), 55 deletions(-) --- a/mm/memcontrol.c~memcg-move-preempt-disable-to-callers-of-memcg_rstat_updated +++ a/mm/memcontrol.c @@ -557,48 +557,22 @@ static u64 flush_last_time; #define FLUSH_TIME (2UL*HZ) -/* - * Accessors to ensure that preemption is disabled on PREEMPT_RT because it can - * not rely on this as part of an acquired spinlock_t lock. These functions are - * never used in hardirq context on PREEMPT_RT and therefore disabling preemtion - * is sufficient. - */ -static void memcg_stats_lock(void) -{ - preempt_disable_nested(); - VM_WARN_ON_IRQS_ENABLED(); -} - -static void __memcg_stats_lock(void) -{ - preempt_disable_nested(); -} - -static void memcg_stats_unlock(void) -{ - preempt_enable_nested(); -} - - static bool memcg_vmstats_needs_flush(struct memcg_vmstats *vmstats) { return atomic64_read(&vmstats->stats_updates) > MEMCG_CHARGE_BATCH * num_online_cpus(); } -static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) +static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val, + int cpu) { struct memcg_vmstats_percpu __percpu *statc_pcpu; struct memcg_vmstats_percpu *statc; - int cpu; unsigned int stats_updates; if (!val) return; - /* Don't assume callers have preemption disabled. */ - cpu = get_cpu(); - cgroup_rstat_updated(memcg->css.cgroup, cpu); statc_pcpu = memcg->vmstats_percpu; for (; statc_pcpu; statc_pcpu = statc->parent_pcpu) { @@ -619,7 +593,6 @@ static inline void memcg_rstat_updated(s stats_updates = this_cpu_xchg(statc_pcpu->stats_updates, 0); atomic64_add(stats_updates, &statc->vmstats->stats_updates); } - put_cpu(); } static void __mem_cgroup_flush_stats(struct mem_cgroup *memcg, bool force) @@ -717,6 +690,7 @@ void __mod_memcg_state(struct mem_cgroup int val) { int i = memcg_stats_index(idx); + int cpu; if (mem_cgroup_disabled()) return; @@ -724,12 +698,14 @@ void __mod_memcg_state(struct mem_cgroup if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) return; - memcg_stats_lock(); + cpu = get_cpu(); + __this_cpu_add(memcg->vmstats_percpu->state[i], val); val = memcg_state_val_in_pages(idx, val); - memcg_rstat_updated(memcg, val); + memcg_rstat_updated(memcg, val, cpu); trace_mod_memcg_state(memcg, idx, val); - memcg_stats_unlock(); + + put_cpu(); } #ifdef CONFIG_MEMCG_V1 @@ -758,6 +734,7 @@ static void __mod_memcg_lruvec_state(str struct mem_cgroup_per_node *pn; struct mem_cgroup *memcg; int i = memcg_stats_index(idx); + int cpu; if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) return; @@ -765,24 +742,7 @@ static void __mod_memcg_lruvec_state(str pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); memcg = pn->memcg; - /* - * The caller from rmap relies on disabled preemption because they never - * update their counter from in-interrupt context. For these two - * counters we check that the update is never performed from an - * interrupt context while other caller need to have disabled interrupt. - */ - __memcg_stats_lock(); - if (IS_ENABLED(CONFIG_DEBUG_VM)) { - switch (idx) { - case NR_ANON_MAPPED: - case NR_FILE_MAPPED: - case NR_ANON_THPS: - WARN_ON_ONCE(!in_task()); - break; - default: - VM_WARN_ON_IRQS_ENABLED(); - } - } + cpu = get_cpu(); /* Update memcg */ __this_cpu_add(memcg->vmstats_percpu->state[i], val); @@ -791,9 +751,10 @@ static void __mod_memcg_lruvec_state(str __this_cpu_add(pn->lruvec_stats_percpu->state[i], val); val = memcg_state_val_in_pages(idx, val); - memcg_rstat_updated(memcg, val); + memcg_rstat_updated(memcg, val, cpu); trace_mod_memcg_lruvec_state(memcg, idx, val); - memcg_stats_unlock(); + + put_cpu(); } /** @@ -873,6 +834,7 @@ void __count_memcg_events(struct mem_cgr unsigned long count) { int i = memcg_events_index(idx); + int cpu; if (mem_cgroup_disabled()) return; @@ -880,11 +842,13 @@ void __count_memcg_events(struct mem_cgr if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) return; - memcg_stats_lock(); + cpu = get_cpu(); + __this_cpu_add(memcg->vmstats_percpu->events[i], count); - memcg_rstat_updated(memcg, count); + memcg_rstat_updated(memcg, count, cpu); trace_count_memcg_events(memcg, idx, count); - memcg_stats_unlock(); + + put_cpu(); } unsigned long memcg_events(struct mem_cgroup *memcg, int event) _ Patches currently in -mm which might be from shakeel.butt@linux.dev are memcg-disable-kmem-charging-in-nmi-for-unsupported-arch.patch memcg-nmi-safe-memcg-stats-for-specific-archs.patch memcg-add-nmi-safe-update-for-memcg_kmem.patch memcg-nmi-safe-slab-stats-updates.patch memcg-make-memcg_rstat_updated-nmi-safe.patch