[v2] mm: Add configuration to control whether vmpressure notifier is enabled

Message ID	1629417219-74853-1-git-send-email-wang.yong12@zte.com.cn (mailing list archive)
State	New
Headers	show Return-Path: <SRS0=4Cc5=NK=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F222160E0B From: yongw.pur@gmail.com To: tj@kernel.org, corbet@lwn.net, akpm@linux-foundation.org, mhocko@kernel.org, vdavydov.dev@gmail.com, tglx@linutronix.de, peterz@infradead.org, shakeelb@google.com, guro@fb.com, alexs@kernel.org, richard.weiyang@gmail.com, sh_def@163.com, sfr@canb.auug.org.au, wang.yong12@zte.com.cn, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, yang.yang29@zte.com.cn Cc: wangyong <wang.yong@zte.com.cn> Subject: [PATCH v2] mm: Add configuration to control whether vmpressure notifier is enabled Date: Thu, 19 Aug 2021 16:53:39 -0700 Message-Id: <1629417219-74853-1-git-send-email-wang.yong12@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	[v2] mm: Add configuration to control whether vmpressure notifier is enabled \| expand [v2] mm: Add configuration to control whether vmpressure notifier is enabled

diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 41191b5..d605035 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -388,6 +388,7 @@ a. Enable CONFIG_CGROUPS b. Enable CONFIG_MEMCG c. Enable CONFIG_MEMCG_SWAP (to use swap extension) d. Enable CONFIG_MEMCG_KMEM (to use kmem extension) +e. Enable CONFIG_MEMCG_VMPRESSURE (to use vmpressure extension) 3.1. Prepare the cgroups (see cgroups.txt, Why are cgroups needed?) ------------------------------------------------------------------- @@ -855,8 +856,8 @@ At reading, current status of OOM is shown. The number of processes belonging to this cgroup killed by any kind of OOM killer. -11. Memory Pressure -=================== +11. Memory Pressure (CONFIG_MEMCG_VMPRESSURE) +============================================= The pressure level notifications can be used to monitor the memory allocation cost; based on the pressure, applications can implement diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 69ded4b..7cf541d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6156,6 +6156,9 @@ vmpoff= [KNL,S390] Perform z/VM CP command after power off. Format: <command> + vmpressure= [KNL] Enable or disable vmpressure notifier. + Format: <bool> + vsyscall= [X86-64] Controls the behavior of vsyscalls (i.e. calls to fixed addresses of 0xffffffffff600x00 from legacy diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h index 6a2f51e..dcae02e 100644 --- a/include/linux/vmpressure.h +++ b/include/linux/vmpressure.h @@ -29,7 +29,8 @@ struct vmpressure { struct mem_cgroup; -#ifdef CONFIG_MEMCG +#ifdef CONFIG_MEMCG_VMPRESSURE +extern bool vmpressure_enable; extern void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, unsigned long scanned, unsigned long reclaimed); extern void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio); @@ -48,5 +49,7 @@ static inline void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, unsigned long scanned, unsigned long reclaimed) {} static inline void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio) {} -#endif /* CONFIG_MEMCG */ +static inline void vmpressure_init(struct vmpressure *vmpr) {} +static inline void vmpressure_cleanup(struct vmpressure *vmpr) {} +#endif /* CONFIG_MEMCG_PRESSURE */ #endif /* __LINUX_VMPRESSURE_H */ diff --git a/init/Kconfig b/init/Kconfig index 71a028d..d3afeb2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -948,6 +948,26 @@ config MEMCG_KMEM depends on MEMCG && !SLOB default y +config MEMCG_VMPRESSURE + bool "Memory pressure notifier" + depends on MEMCG + default y + help + Vmpressure extension is used to monitor the memory allocation cost. + The pressure level can be set according to the use scenario and + application will be notified through eventfd when memory pressure is at + the specific level (or higher). + +config VMPRESSURE_DEFAULT_DISABLED + bool "Require boot parameter to enable memory pressure notifier" + depends on MEMCG_VMPRESSURE + default n + help + If set, memory pressure notifier will be disabled but can be + enabled through passing vmpressure=1 on the kernel commandline + during boot. + For those who want to use memory pressure notifier flexibly. + config BLK_CGROUP bool "IO controller" depends on BLOCK diff --git a/mm/Makefile b/mm/Makefile index 970604e..e4f99c1 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -92,7 +92,8 @@ obj-$(CONFIG_MEMTEST) += memtest.o obj-$(CONFIG_MIGRATION) += migrate.o obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o obj-$(CONFIG_PAGE_COUNTER) += page_counter.o -obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o +obj-$(CONFIG_MEMCG) += memcontrol.o +obj-$(CONFIG_MEMCG_VMPRESSURE) += vmpressure.o obj-$(CONFIG_MEMCG_SWAP) += swap_cgroup.o obj-$(CONFIG_CGROUP_HUGETLB) += hugetlb_cgroup.o obj-$(CONFIG_GUP_TEST) += gup_test.o diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e55f422..975e098 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -248,6 +248,7 @@ static inline bool should_force_charge(void) (current->flags & PF_EXITING); } +#ifdef CONFIG_MEMCG_VMPRESSURE /* Some nice accessors for the vmpressure. */ struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) { @@ -260,6 +261,7 @@ struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr) { return container_of(vmpr, struct mem_cgroup, vmpressure); } +#endif #ifdef CONFIG_MEMCG_KMEM extern spinlock_t css_set_lock; @@ -4823,9 +4825,12 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, } else if (!strcmp(name, "memory.oom_control")) { event->register_event = mem_cgroup_oom_register_event; event->unregister_event = mem_cgroup_oom_unregister_event; - } else if (!strcmp(name, "memory.pressure_level")) { +#ifdef CONFIG_MEMCG_VMPRESSURE + } else if (vmpressure_enable && + !strcmp(name, "memory.pressure_level")) { event->register_event = vmpressure_register_event; event->unregister_event = vmpressure_unregister_event; +#endif } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { event->register_event = memsw_cgroup_usage_register_event; event->unregister_event = memsw_cgroup_usage_unregister_event; diff --git a/mm/vmpressure.c b/mm/vmpressure.c index 76518e4..b0d4358 100644 --- a/mm/vmpressure.c +++ b/mm/vmpressure.c @@ -67,6 +67,19 @@ static const unsigned int vmpressure_level_critical = 95; */ static const unsigned int vmpressure_level_critical_prio = ilog2(100 / 10); +DEFINE_STATIC_KEY_FALSE(vmpressure_disabled); +#ifdef CONFIG_VMPRESSURE_DEFAULT_DISABLED +bool vmpressure_enable; +#else +bool vmpressure_enable = true; +#endif +static int __init setup_vmpressure(char *str) +{ + return kstrtobool(str, &vmpressure_enable) == 0; +} +__setup("vmpressure=", setup_vmpressure); + + static struct vmpressure *work_to_vmpressure(struct work_struct *work) { return container_of(work, struct vmpressure, work); @@ -246,6 +259,9 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, vmpr = memcg_to_vmpressure(memcg); + if (static_branch_likely(&vmpressure_disabled)) + return; + /* * Here we only want to account pressure that userland is able to * help us with. For example, suppose that DMA zone is under @@ -326,6 +342,8 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, */ void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio) { + if (static_branch_likely(&vmpressure_disabled)) + return; /* * We only use prio for accounting critical level. For more info * see comment for vmpressure_level_critical_prio variable above. @@ -450,6 +468,11 @@ void vmpressure_unregister_event(struct mem_cgroup *memcg, */ void vmpressure_init(struct vmpressure *vmpr) { + if (!vmpressure_enable) { + static_branch_enable(&vmpressure_disabled); + return; + } + spin_lock_init(&vmpr->sr_lock); mutex_init(&vmpr->events_lock); INIT_LIST_HEAD(&vmpr->events); @@ -465,6 +488,9 @@ void vmpressure_init(struct vmpressure *vmpr) */ void vmpressure_cleanup(struct vmpressure *vmpr) { + + if (static_branch_likely(&vmpressure_disabled)) + return; /* * Make sure there is no pending work before eventfd infrastructure * goes away.

[v2] mm: Add configuration to control whether vmpressure notifier is enabled

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