From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEBA7CD11DD for ; Wed, 27 Mar 2024 21:31:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A19CA6B0099; Wed, 27 Mar 2024 17:31:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 97B776B009A; Wed, 27 Mar 2024 17:31:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 70D586B009B; Wed, 27 Mar 2024 17:31:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 4ECBB6B0099 for ; Wed, 27 Mar 2024 17:31:44 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 16A8C140593 for ; Wed, 27 Mar 2024 21:31:44 +0000 (UTC) X-FDA: 81944116128.10.3D2918B Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) by imf02.hostedemail.com (Postfix) with ESMTP id 347A18000A for ; Wed, 27 Mar 2024 21:31:41 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=UawUHdMB; spf=pass (imf02.hostedemail.com: domain of 3PZAEZgcKCKYeaGTINaMUUMRK.IUSROTad-SSQbGIQ.UXM@flex--yuanchu.bounces.google.com designates 209.85.128.201 as permitted sender) smtp.mailfrom=3PZAEZgcKCKYeaGTINaMUUMRK.IUSROTad-SSQbGIQ.UXM@flex--yuanchu.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711575102; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=A565PQouZoECoC+bAbMpMjHjbmuhcXoGplNwxvsLI/Q=; b=nAYcW8mfl2QlhZheKoMNcSDULW1M8EfZGyJyPe2EhOjk2t0UA8/Mzhs3k98Vw22Wob+WaT pC3e3wKbbdIE1ChUsVLs8rC76y+mih3+r1z7o9aano/Tp8GaLSNCYc0/XZ/k3ipV5xR/gc 1Jb5GEzIQojwrfiz7gEI44GfMakHVww= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=UawUHdMB; spf=pass (imf02.hostedemail.com: domain of 3PZAEZgcKCKYeaGTINaMUUMRK.IUSROTad-SSQbGIQ.UXM@flex--yuanchu.bounces.google.com designates 209.85.128.201 as permitted sender) smtp.mailfrom=3PZAEZgcKCKYeaGTINaMUUMRK.IUSROTad-SSQbGIQ.UXM@flex--yuanchu.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711575102; a=rsa-sha256; cv=none; b=D7vRHE1wvBLT28+nq2a87pnqUIeBcRUlHeZVyfvcXTp7cOE1IUpLfyPMGKYLJaW+db5tQx NcZDdvYXspRICUJ6+HJi20RxPZF7tHq7woGl8MtLvdbwxdmkZL3yX6dR20DaIOXtZ1xiv6 jYEp1b/qyNWG0m/KsSu/fksC51Ql7NY= Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-60a0b18e52dso4213687b3.1 for ; Wed, 27 Mar 2024 14:31:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1711575101; x=1712179901; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=A565PQouZoECoC+bAbMpMjHjbmuhcXoGplNwxvsLI/Q=; b=UawUHdMBudKagJOL1/T3M5gLUqDVf7YriF02EM9JAzeqPgZK4e4KyyIduhVMFIglNb QD42AvR1hRrfPMWHD9U56+UzfHNwKgyeM4l4mpbiyoxfzUBizClh4QmRYr1GWLa+83rz iMLaL2W1jJ8+KqOnfIm7rjx0VG+0Rti0xy32wd74uzJ2KWODJEg8k5nC8wy9aLbUshac BWDTdXBBkw7YgUThfGYWcsab7vjUYiUML+VLZhXCSwMLm4Ovkb6qLsm2y0Xd+0teZol3 3USj1t9BBLvlQgl5ISBbTTGkoZvry1oHjUyEhlGKL8Jl3V0wQsoNYk/H7BWdgWTgVzw3 ov0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711575101; x=1712179901; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=A565PQouZoECoC+bAbMpMjHjbmuhcXoGplNwxvsLI/Q=; b=Jy4an/73Giiqk/8TPxkWaqeTptMRVxwXzwjs8i4oenbyyfasA88DOWw0GYKsbM+/7J C4yZhj4d1X3MnFCg8HGWudQYjrAIPEDO85GKnhi6tmhZ7EkUQfiibqTHE0Bq36oYhuF7 2B//fGw2sa8ePmm8c7Sd1sWp4iy+NQID87xxbmxNfw+DC3WzdEV2hFkrDRk8DRoM4RVY pyVUep83eNTFHZ/3E/QxOcBdAq/fIUeof/iUtL4AqvLjrwwOO+uvBfV24c9S7yfTOPq7 VDl71wuJT5mdjG6501m+TNh/CogdGQ7XXqpQ092Y9lmPBE/RbyFxENAZvbKkJhIfTKH0 rKUw== X-Forwarded-Encrypted: i=1; AJvYcCVtK5EAQ4jCFO1MXN3G2Z87vxQnBZigKMBBtuVD9uKJttiliWJVGx9BjlwOoxn7CNrngEtvI0vn3sG68J1y36q1qI0= X-Gm-Message-State: AOJu0YzFNDv3mnplK88rVa9Ax8b1YkeXuaw3SVeam8BsBh+qBXd6yv0C qx3QiCq4qTKGbCmOrEvq0bPaqALqLb4SqPeGB59TQhOjiaeYINco/ldMC7QjzzNXE5s0EWIjwQU pVd+MLw== X-Google-Smtp-Source: AGHT+IGWjQUNRXXoGUh5+QqHFNkK8JcuM0kAdyJ/QDj3Y482hU2DxaC1k/t+Vf+seKF4W2aB0l9ObuFk2jZg X-Received: from yuanchu-desktop.svl.corp.google.com ([2620:15c:2a3:200:6df3:ef42:a58e:a6b1]) (user=yuanchu job=sendgmr) by 2002:a0d:df0d:0:b0:611:3077:2de7 with SMTP id i13-20020a0ddf0d000000b0061130772de7mr101184ywe.3.1711575101306; Wed, 27 Mar 2024 14:31:41 -0700 (PDT) Date: Wed, 27 Mar 2024 14:31:06 -0700 In-Reply-To: <20240327213108.2384666-1-yuanchu@google.com> Mime-Version: 1.0 References: <20240327213108.2384666-1-yuanchu@google.com> X-Mailer: git-send-email 2.44.0.396.g6e790dbe36-goog Message-ID: <20240327213108.2384666-8-yuanchu@google.com> Subject: [RFC PATCH v3 7/8] mm: add kernel aging thread for workingset reporting From: Yuanchu Xie To: David Hildenbrand , "Aneesh Kumar K.V" , Khalid Aziz , Henry Huang , Yu Zhao , Dan Williams , Gregory Price , Huang Ying Cc: Wei Xu , David Rientjes , Greg Kroah-Hartman , "Rafael J. Wysocki" , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Shuah Khan , Yosry Ahmed , Matthew Wilcox , Sudarshan Rajagopalan , Kairui Song , "Michael S. Tsirkin" , Vasily Averin , Nhat Pham , Miaohe Lin , Qi Zheng , Abel Wu , "Vishal Moola (Oracle)" , Kefeng Wang , Yuanchu Xie , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 347A18000A X-Rspam-User: X-Stat-Signature: fwjq4639wei9oddr6png1xuni5qis6e5 X-Rspamd-Server: rspam01 X-HE-Tag: 1711575101-689709 X-HE-Meta: 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 6pm5CVGW 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: For reliable and timely aging on memcgs, one has to read the page age histograms on time. A kernel thread makes it easier by aging memcgs with valid page_age_intervals and refresh_interval when they can be refreshed, and also reduces the latency of any userspace consumers of the page age histogram. The kernel aging thread is gated behind CONFIG_WORKINGSET_REPORT_AGING. Debugging stats may be added in the future for when aging cannot keep up with the configured refresh_interval. Signed-off-by: Yuanchu Xie --- include/linux/workingset_report.h | 11 ++- mm/Kconfig | 6 ++ mm/Makefile | 1 + mm/memcontrol.c | 11 ++- mm/workingset_report.c | 14 +++- mm/workingset_report_aging.c | 127 ++++++++++++++++++++++++++++++ 6 files changed, 163 insertions(+), 7 deletions(-) create mode 100644 mm/workingset_report_aging.c diff --git a/include/linux/workingset_report.h b/include/linux/workingset_report.h index e908c5678b1e..759486a3a285 100644 --- a/include/linux/workingset_report.h +++ b/include/linux/workingset_report.h @@ -77,9 +77,18 @@ void wsr_destroy(struct lruvec *lruvec); * The next refresh time is stored in refresh_time. */ bool wsr_refresh_report(struct wsr_state *wsr, struct mem_cgroup *root, - struct pglist_data *pgdat); + struct pglist_data *pgdat, unsigned long *refresh_time); void wsr_register_node(struct node *node); void wsr_unregister_node(struct node *node); + +#ifdef CONFIG_WORKINGSET_REPORT_AGING +void wsr_wakeup_aging_thread(void); +#else /* CONFIG_WORKINGSET_REPORT_AGING */ +static inline void wsr_wakeup_aging_thread(void) +{ +} +#endif /* CONFIG_WORKINGSET_REPORT_AGING */ + #else static inline void wsr_init(struct lruvec *lruvec) { diff --git a/mm/Kconfig b/mm/Kconfig index 212f203b10b9..1e6aa1bd63f2 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1270,6 +1270,12 @@ config WORKINGSET_REPORT This option exports stats and events giving the user more insight into its memory working set. +config WORKINGSET_REPORT_AGING + bool "Workingset report kernel aging thread" + depends on WORKINGSET_REPORT + help + Performs aging on memcgs with their configured refresh intervals. + source "mm/damon/Kconfig" endmenu diff --git a/mm/Makefile b/mm/Makefile index 57093657030d..7caae7f2d6cf 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -93,6 +93,7 @@ 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_WORKINGSET_REPORT) += workingset_report.o +obj-$(CONFIG_WORKINGSET_REPORT_AGING) += workingset_report_aging.o ifdef CONFIG_SWAP obj-$(CONFIG_MEMCG) += swap_cgroup.o endif diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2a39a4445bb7..86e15b9fc8e2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7102,6 +7102,8 @@ static ssize_t memory_ws_page_age_intervals_write(struct kernfs_open_file *of, old = xchg(&wsr->page_age, page_age); mutex_unlock(&wsr->page_age_lock); kfree(old); + if (err && READ_ONCE(wsr->refresh_interval)) + wsr_wakeup_aging_thread(); return nbytes; failed: kfree(page_age); @@ -7227,14 +7229,17 @@ static ssize_t memory_ws_refresh_interval_write(struct kernfs_open_file *of, { unsigned int nid, msecs; struct wsr_state *wsr; + unsigned long old_interval; struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); ssize_t ret = memory_wsr_threshold_parse(buf, nbytes, &nid, &msecs); if (ret < 0) return ret; - wsr = &mem_cgroup_lruvec(memcg, NODE_DATA(nid))->wsr; + old_interval = jiffies_to_msecs(READ_ONCE(wsr->refresh_interval)); WRITE_ONCE(wsr->refresh_interval, msecs_to_jiffies(msecs)); + if (msecs && (!old_interval || jiffies_to_msecs(old_interval) > msecs)) + wsr_wakeup_aging_thread(); return ret; } @@ -7285,7 +7290,7 @@ static int memory_ws_page_age_show(struct seq_file *m, void *v) if (!READ_ONCE(wsr->page_age)) continue; - wsr_refresh_report(wsr, memcg, NODE_DATA(nid)); + wsr_refresh_report(wsr, memcg, NODE_DATA(nid), NULL); mutex_lock(&wsr->page_age_lock); if (!wsr->page_age) goto unlock; @@ -7325,7 +7330,7 @@ static int memory_ws_reaccess_histogram_show(struct seq_file *m, void *v) if (!reaccess) goto unlock; - wsr_refresh_report(wsr, memcg, NODE_DATA(nid)); + wsr_refresh_report(wsr, memcg, NODE_DATA(nid), NULL); seq_printf(m, "N%d\n", nid); for (bin = reaccess->bins.bins; diff --git a/mm/workingset_report.c b/mm/workingset_report.c index 504d840bbe6a..da658967eac2 100644 --- a/mm/workingset_report.c +++ b/mm/workingset_report.c @@ -234,7 +234,7 @@ static void refresh_aggregate(struct wsr_page_age_histo *page_age, } bool wsr_refresh_report(struct wsr_state *wsr, struct mem_cgroup *root, - struct pglist_data *pgdat) + struct pglist_data *pgdat, unsigned long *refresh_time) { struct wsr_page_age_histo *page_age = NULL; unsigned long refresh_interval = READ_ONCE(wsr->refresh_interval); @@ -253,6 +253,8 @@ bool wsr_refresh_report(struct wsr_state *wsr, struct mem_cgroup *root, goto unlock; refresh_scan(wsr, root, pgdat, refresh_interval); refresh_aggregate(page_age, root, pgdat); + if (refresh_time) + *refresh_time = page_age->timestamp + refresh_interval; unlock: mutex_unlock(&wsr->page_age_lock); @@ -564,12 +566,16 @@ static ssize_t refresh_interval_store(struct kobject *kobj, unsigned int interval; int err; struct wsr_state *wsr = kobj_to_wsr(kobj); + unsigned long old_interval; err = kstrtouint(buf, 0, &interval); if (err) return err; - WRITE_ONCE(wsr->refresh_interval, msecs_to_jiffies(interval)); + old_interval = xchg(&wsr->refresh_interval, msecs_to_jiffies(interval)); + if (interval && + (!old_interval || jiffies_to_msecs(old_interval) > interval)) + wsr_wakeup_aging_thread(); return len; } @@ -642,6 +648,8 @@ static ssize_t page_age_intervals_store(struct kobject *kobj, mutex_unlock(&wsr->page_age_lock); kfree(old); kfree(buf); + if (err && READ_ONCE(wsr->refresh_interval)) + wsr_wakeup_aging_thread(); return len; failed: kfree(page_age); @@ -663,7 +671,7 @@ static ssize_t page_age_show(struct kobject *kobj, struct kobj_attribute *attr, if (!READ_ONCE(wsr->page_age)) return -EINVAL; - wsr_refresh_report(wsr, NULL, kobj_to_pgdat(kobj)); + wsr_refresh_report(wsr, NULL, kobj_to_pgdat(kobj), NULL); mutex_lock(&wsr->page_age_lock); if (!wsr->page_age) { diff --git a/mm/workingset_report_aging.c b/mm/workingset_report_aging.c new file mode 100644 index 000000000000..91ad5020778a --- /dev/null +++ b/mm/workingset_report_aging.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Workingset report kernel aging thread + * + * Performs aging on behalf of memcgs with their configured refresh interval. + * While a userspace program can periodically read the page age breakdown + * per-memcg and trigger aging, the kernel performing aging is less overhead, + * more consistent, and more reliable for the use case where every memcg should + * be aged according to their refresh interval. + */ +#define pr_fmt(fmt) "workingset report aging: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static DECLARE_WAIT_QUEUE_HEAD(aging_wait); +static bool refresh_pending; + +static bool do_aging_node(int nid, unsigned long *next_wake_time) +{ + struct mem_cgroup *memcg; + bool should_wait = true; + struct pglist_data *pgdat = NODE_DATA(nid); + + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat); + struct wsr_state *wsr = &lruvec->wsr; + unsigned long refresh_time; + + /* use returned time to decide when to wake up next */ + if (wsr_refresh_report(wsr, memcg, pgdat, &refresh_time)) { + if (should_wait) { + should_wait = false; + *next_wake_time = refresh_time; + } else if (time_before(refresh_time, *next_wake_time)) { + *next_wake_time = refresh_time; + } + } + + cond_resched(); + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL))); + + return should_wait; +} + +static int do_aging(void *unused) +{ + while (!kthread_should_stop()) { + int nid; + long timeout_ticks; + unsigned long next_wake_time; + bool should_wait = true; + + WRITE_ONCE(refresh_pending, false); + for_each_node_state(nid, N_MEMORY) { + unsigned long node_next_wake_time; + + if (do_aging_node(nid, &node_next_wake_time)) + continue; + if (should_wait) { + should_wait = false; + next_wake_time = node_next_wake_time; + } else if (time_before(node_next_wake_time, + next_wake_time)) { + next_wake_time = node_next_wake_time; + } + } + + if (should_wait) { + wait_event_interruptible(aging_wait, refresh_pending); + continue; + } + + /* sleep until next aging */ + timeout_ticks = next_wake_time - jiffies; + if (timeout_ticks > 0 && + timeout_ticks != MAX_SCHEDULE_TIMEOUT) { + schedule_timeout_idle(timeout_ticks); + continue; + } + } + return 0; +} + +/* Invoked when refresh_interval shortens or changes to a non-zero value. */ +void wsr_wakeup_aging_thread(void) +{ + WRITE_ONCE(refresh_pending, true); + wake_up_interruptible(&aging_wait); +} + +static struct task_struct *aging_thread; + +static int aging_init(void) +{ + struct task_struct *task; + + task = kthread_run(do_aging, NULL, "kagingd"); + + if (IS_ERR(task)) { + pr_err("Failed to create aging kthread\n"); + return PTR_ERR(task); + } + + aging_thread = task; + pr_info("module loaded\n"); + return 0; +} + +static void aging_exit(void) +{ + kthread_stop(aging_thread); + aging_thread = NULL; + pr_info("module unloaded\n"); +} + +module_init(aging_init); +module_exit(aging_exit); -- 2.44.0.396.g6e790dbe36-goog