From: Thomas Gleixner <tglx@linutronix.de> To: LKML <linux-kernel@vger.kernel.org> Cc: linux-mm@kvack.org, Andrey Ryabinin <aryabinin@virtuozzo.com>, Michal Hocko <mhocko@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Vlastimil Babka <vbabka@suse.cz>, Vladimir Davydov <vdavydov.dev@gmail.com>, Peter Zijlstra <peterz@infradead.org> Subject: [patch V2 1/2] mm: swap: Provide lru_add_drain_all_cpuslocked() Date: Tue, 04 Jul 2017 11:32:33 +0200 [thread overview] Message-ID: <20170704093421.419329357@linutronix.de> (raw) In-Reply-To: 20170704093232.995040438@linutronix.de [-- Attachment #1: mm--swap--Provide-lru_add_drain_cpuslocked--.patch --] [-- Type: text/plain, Size: 2274 bytes --] The rework of the cpu hotplug locking unearthed potential deadlocks with the memory hotplug locking code. The solution for these is to rework the memory hotplug locking code as well and take the cpu hotplug lock before the memory hotplug lock in mem_hotplug_begin(), but this will cause a recursive locking of the cpu hotplug lock when the memory hotplug code calls lru_add_drain_all(). Split out the inner workings of lru_add_drain_all() into lru_add_drain_all_cpuslocked() so this function can be invoked from the memory hotplug code with the cpu hotplug lock held. Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> --- include/linux/swap.h | 1 + mm/swap.c | 11 ++++++++--- 2 files changed, 9 insertions(+), 3 deletions(-) --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -277,6 +277,7 @@ extern void mark_page_accessed(struct pa extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); extern void lru_add_drain_all(void); +extern void lru_add_drain_all_cpuslocked(void); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_file_page(struct page *page); extern void mark_page_lazyfree(struct page *page); --- a/mm/swap.c +++ b/mm/swap.c @@ -687,7 +687,7 @@ static void lru_add_drain_per_cpu(struct static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); -void lru_add_drain_all(void) +void lru_add_drain_all_cpuslocked(void) { static DEFINE_MUTEX(lock); static struct cpumask has_work; @@ -701,7 +701,6 @@ void lru_add_drain_all(void) return; mutex_lock(&lock); - get_online_cpus(); cpumask_clear(&has_work); for_each_online_cpu(cpu) { @@ -721,10 +720,16 @@ void lru_add_drain_all(void) for_each_cpu(cpu, &has_work) flush_work(&per_cpu(lru_add_drain_work, cpu)); - put_online_cpus(); mutex_unlock(&lock); } +void lru_add_drain_all(void) +{ + get_online_cpus(); + lru_add_drain_all_cpuslocked(); + put_online_cpus(); +} + /** * release_pages - batched put_page() * @pages: array of pages to release
WARNING: multiple messages have this Message-ID (diff)
From: Thomas Gleixner <tglx@linutronix.de> To: LKML <linux-kernel@vger.kernel.org> Cc: linux-mm@kvack.org, Andrey Ryabinin <aryabinin@virtuozzo.com>, Michal Hocko <mhocko@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Vlastimil Babka <vbabka@suse.cz>, Vladimir Davydov <vdavydov.dev@gmail.com>, Peter Zijlstra <peterz@infradead.org> Subject: [patch V2 1/2] mm: swap: Provide lru_add_drain_all_cpuslocked() Date: Tue, 04 Jul 2017 11:32:33 +0200 [thread overview] Message-ID: <20170704093421.419329357@linutronix.de> (raw) In-Reply-To: 20170704093232.995040438@linutronix.de [-- Attachment #1: mm--swap--Provide-lru_add_drain_cpuslocked--.patch --] [-- Type: text/plain, Size: 2501 bytes --] The rework of the cpu hotplug locking unearthed potential deadlocks with the memory hotplug locking code. The solution for these is to rework the memory hotplug locking code as well and take the cpu hotplug lock before the memory hotplug lock in mem_hotplug_begin(), but this will cause a recursive locking of the cpu hotplug lock when the memory hotplug code calls lru_add_drain_all(). Split out the inner workings of lru_add_drain_all() into lru_add_drain_all_cpuslocked() so this function can be invoked from the memory hotplug code with the cpu hotplug lock held. Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> --- include/linux/swap.h | 1 + mm/swap.c | 11 ++++++++--- 2 files changed, 9 insertions(+), 3 deletions(-) --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -277,6 +277,7 @@ extern void mark_page_accessed(struct pa extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); extern void lru_add_drain_all(void); +extern void lru_add_drain_all_cpuslocked(void); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_file_page(struct page *page); extern void mark_page_lazyfree(struct page *page); --- a/mm/swap.c +++ b/mm/swap.c @@ -687,7 +687,7 @@ static void lru_add_drain_per_cpu(struct static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); -void lru_add_drain_all(void) +void lru_add_drain_all_cpuslocked(void) { static DEFINE_MUTEX(lock); static struct cpumask has_work; @@ -701,7 +701,6 @@ void lru_add_drain_all(void) return; mutex_lock(&lock); - get_online_cpus(); cpumask_clear(&has_work); for_each_online_cpu(cpu) { @@ -721,10 +720,16 @@ void lru_add_drain_all(void) for_each_cpu(cpu, &has_work) flush_work(&per_cpu(lru_add_drain_work, cpu)); - put_online_cpus(); mutex_unlock(&lock); } +void lru_add_drain_all(void) +{ + get_online_cpus(); + lru_add_drain_all_cpuslocked(); + put_online_cpus(); +} + /** * release_pages - batched put_page() * @pages: array of pages to release -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-07-04 9:36 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-07-04 9:32 [patch V2 0/2] mm/memory_hotplug: Cure potential deadlocks vs. cpu hotplug lock Thomas Gleixner 2017-07-04 9:32 ` Thomas Gleixner 2017-07-04 9:32 ` Thomas Gleixner [this message] 2017-07-04 9:32 ` [patch V2 1/2] mm: swap: Provide lru_add_drain_all_cpuslocked() Thomas Gleixner 2017-07-04 10:58 ` Michal Hocko 2017-07-04 10:58 ` Michal Hocko 2017-07-04 12:48 ` Thomas Gleixner 2017-07-04 12:48 ` Thomas Gleixner 2017-07-04 12:52 ` Michal Hocko 2017-07-04 12:52 ` Michal Hocko 2017-07-04 12:07 ` Vlastimil Babka 2017-07-04 12:07 ` Vlastimil Babka 2017-07-04 12:35 ` Thomas Gleixner 2017-07-04 12:35 ` Thomas Gleixner 2017-07-04 9:32 ` [patch V2 2/2] mm/memory-hotplug: Switch locking to a percpu rwsem Thomas Gleixner 2017-07-04 9:32 ` Thomas Gleixner 2017-07-04 10:59 ` Michal Hocko 2017-07-04 10:59 ` Michal Hocko 2017-07-04 12:10 ` Vlastimil Babka 2017-07-04 12:10 ` Vlastimil Babka 2017-07-04 12:49 ` Thomas Gleixner 2017-07-04 12:49 ` Thomas Gleixner 2017-07-04 15:01 ` Davidlohr Bueso 2017-07-04 15:01 ` Davidlohr Bueso 2017-07-04 15:22 ` Davidlohr Bueso 2017-07-04 15:22 ` Davidlohr Bueso 2017-07-04 15:32 ` Thomas Gleixner 2017-07-04 15:32 ` Thomas Gleixner 2017-07-04 15:42 ` Davidlohr Bueso 2017-07-04 15:42 ` Davidlohr Bueso 2017-07-05 21:53 ` [patch V2 0/2] mm/memory_hotplug: Cure potential deadlocks vs. cpu hotplug lock Andrew Morton 2017-07-05 21:53 ` Andrew Morton 2017-07-06 6:34 ` Thomas Gleixner 2017-07-06 6:34 ` Thomas Gleixner
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