From nobody Mon Feb 9 06:24:35 2026 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C84FE1A2C39 for ; Tue, 13 Aug 2024 16:59:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723568385; cv=none; b=Ae60kwI63Tl+hrCxei+Csl4626Ru6oHsHE82N7TSwgkDQRstOCOwNJpQghahUcue/z7rp5+S7sitYYwNIUhRtGs7stxiTk6lVKMOa3gaWXV4rF0VvPdZL3yfDz6/aARn52LGcKso4z/wwA2wIsHjiYZJMmJgFQgUMc4YZ2QtdyE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723568385; c=relaxed/simple; bh=uUt4ZAicTtOcUFBajc2Rcm/DS6stfUhYzd+Acgyt79g=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=cvWyVTDZ4zt7mWO93BLZUDxvcxHX7lj5aSoa2wRJ+CHZVinWPfuSb8ZyzHkk6NNeItBogzuLyM4ZzK7kYzoRP1yU0ABAwK8wB6FhiUksd6e0V98+9CvveS1OvwVwdF/c1OLHheMSIdSZnemM58e0HhjsU7aYtfILmpZHja75YnY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--yuanchu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=IlJ+ydgf; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--yuanchu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IlJ+ydgf" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-666010fb35cso1071527b3.0 for ; Tue, 13 Aug 2024 09:59:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1723568382; x=1724173182; darn=vger.kernel.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=I1JUyOR+BauD0beWrpDUPXKr0GpTowWtPDSwnxHbi4c=; b=IlJ+ydgfsQVGD8V5EZalojt0t8crnWOVXavzywaQ7Jf5nNZbWQktI6u+EEWwF3OcBi PzZFmPY9kXHnCTqhgo9g6R1R88vbfDsMpaDEDHz1v9AVFAmJRjeWSUFQgl2xu/zXWwri qYGYYLfuHxweY+fWH6CNZf97W3w6dPIbIYoBPXHGSoTZfwK62XrATImy+GfwasCNV7Rt fhNGrdRUk8NnSyjNhO1x0MTz9Cys0+MNPZ/hbRCiQoePfPYGo2OGEaMhtK7oZiLQJyjT uhkSfMIR0ivCHBGotLCpQUVa1/AUBje7cxFnexmDIT2V/n6CLqVTc9s+RWzcI+orO26B HG2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723568382; x=1724173182; 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=I1JUyOR+BauD0beWrpDUPXKr0GpTowWtPDSwnxHbi4c=; b=wd8oDD593MELyw21tcfSIEH3pISP2UWdktZPtORtRGjwBJ9u+CQNyBFiasfPlhmTPs DpqQpYjatB7FnhQiICeViY5gA9bbN3sTjoiTSBg8t+0Go2HZThvGogGiSXMcPOSeB8d9 eShv7Mv5LtvbWg+xUXlIiHV6OGr8yA7TRKesTZRuwZN5OGZQbMzeUdlZMHppldbJ5bCW 99QftfpbJEm6BRfTixVkyiDtpqmJuP7vhwBdVsvYZ58NiF+HFrjTIsBFJlG/tOFsrLkr WL3Mz236Tb79kyQ0ilc0oYBgLpPV2swJx+M7xF3zG+3qtjpJ7p2lKQdN+Jcjq2WqbOp5 7I8A== X-Forwarded-Encrypted: i=1; AJvYcCVZ7e7w2mtESOQYB4fwv2mLORGyKW0ti2LivJi1vmS4Yb8u33zfzD4GL2xqh8PHrq0eDjDkp8sTWsZV/EXsFIUnJ4Eu1QnjPYweL1Gf X-Gm-Message-State: AOJu0Yxv6D3WKQ4D3tZyvnE9We3GSOah8VDF8TtBG2CI41v6ap/jEJB5 7LMoHdG9cyMtHEvdaRFLkJRb3AaLsPz+8IlHx3hj9139JdeWUW6SXedcfYRWiiYqhTtsKW//t/N GUkk2NA== X-Google-Smtp-Source: AGHT+IGF6gcvOUuK0qRwt2F4MDLyEzr3H7dooXhW2VhDhQ7vMG1kJd5bUtwNOeRY1xrvYnGAuUjldLTxpbDJ X-Received: from yuanchu-desktop.svl.corp.google.com ([2620:15c:2a3:200:b50c:66e8:6532:a371]) (user=yuanchu job=sendgmr) by 2002:a0d:ce01:0:b0:6a1:741b:b723 with SMTP id 00721157ae682-6a9ea8e5238mr545567b3.5.1723568381863; Tue, 13 Aug 2024 09:59:41 -0700 (PDT) Date: Tue, 13 Aug 2024 09:56:14 -0700 In-Reply-To: <20240813165619.748102-1-yuanchu@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240813165619.748102-1-yuanchu@google.com> X-Mailer: git-send-email 2.46.0.76.ge559c4bf1a-goog Message-ID: <20240813165619.748102-4-yuanchu@google.com> Subject: [PATCH v3 3/7] mm: report workingset during memory pressure driven scanning From: Yuanchu Xie To: David Hildenbrand , "Aneesh Kumar K.V" , Khalid Aziz , Henry Huang , Yu Zhao , Dan Williams , Gregory Price , Huang Ying , Andrew Morton , Lance Yang , Randy Dunlap , Muhammad Usama Anjum Cc: Kalesh Singh , Wei Xu , David Rientjes , Greg Kroah-Hartman , "Rafael J. Wysocki" , 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-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When a node reaches its low watermarks and wakes up kswapd, notify all userspace programs waiting on the workingset page age histogram of the memory pressure, so a userspace agent can read the workingset report in time and make policy decisions, such as logging, oom-killing, or migration. Sysfs interface: /sys/devices/system/node/nodeX/workingset_report/report_threshold time in milliseconds that specifies how often the userspace agent can be notified for node memory pressure. Signed-off-by: Yuanchu Xie Change-Id: Ib1fdb726da921e8d467822a99da8f384c6181951 --- include/linux/workingset_report.h | 4 +++ mm/internal.h | 12 ++++++++ mm/vmscan.c | 46 +++++++++++++++++++++++++++++++ mm/workingset_report.c | 43 ++++++++++++++++++++++++++++- 4 files changed, 104 insertions(+), 1 deletion(-) diff --git a/include/linux/workingset_report.h b/include/linux/workingset_r= eport.h index 8bae6a600410..2ec8b927b200 100644 --- a/include/linux/workingset_report.h +++ b/include/linux/workingset_report.h @@ -37,7 +37,11 @@ struct wsr_page_age_histo { }; =20 struct wsr_state { + unsigned long report_threshold; unsigned long refresh_interval; + + struct kernfs_node *page_age_sys_file; + /* breakdown of workingset by page age */ struct mutex page_age_lock; struct wsr_page_age_histo *page_age; diff --git a/mm/internal.h b/mm/internal.h index f7d790f5d41c..19af882c506e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -416,6 +416,18 @@ bool try_to_inc_max_seq(struct lruvec *lruvec, unsigne= d long seq, bool can_swap, bool force_scan); void set_task_reclaim_state(struct task_struct *task, struct reclaim_state= *rs); =20 +#ifdef CONFIG_WORKINGSET_REPORT +/* + * in mm/wsr.c + */ +void notify_workingset(struct mem_cgroup *memcg, struct pglist_data *pgdat= ); +#else +static inline void notify_workingset(struct mem_cgroup *memcg, + struct pglist_data *pgdat) +{ +} +#endif + /* * in mm/rmap.c: */ diff --git a/mm/vmscan.c b/mm/vmscan.c index 8ab1b456d2cf..b07fd2016c75 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2574,6 +2574,15 @@ static bool can_age_anon_pages(struct pglist_data *p= gdat, return can_demote(pgdat->node_id, sc); } =20 +#ifdef CONFIG_WORKINGSET_REPORT +static void try_to_report_workingset(struct pglist_data *pgdat, struct sca= n_control *sc); +#else +static inline void try_to_report_workingset(struct pglist_data *pgdat, + struct scan_control *sc) +{ +} +#endif + #ifdef CONFIG_LRU_GEN =20 #ifdef CONFIG_LRU_GEN_ENABLED @@ -4000,6 +4009,8 @@ static void lru_gen_age_node(struct pglist_data *pgda= t, struct scan_control *sc) =20 set_initial_priority(pgdat, sc); =20 + try_to_report_workingset(pgdat, sc); + memcg =3D mem_cgroup_iter(NULL, NULL, NULL); do { struct lruvec *lruvec =3D mem_cgroup_lruvec(memcg, pgdat); @@ -5640,6 +5651,38 @@ static int __init init_lru_gen(void) }; late_initcall(init_lru_gen); =20 +#ifdef CONFIG_WORKINGSET_REPORT +static void try_to_report_workingset(struct pglist_data *pgdat, + struct scan_control *sc) +{ + struct mem_cgroup *memcg =3D sc->target_mem_cgroup; + struct wsr_state *wsr =3D &mem_cgroup_lruvec(memcg, pgdat)->wsr; + unsigned long threshold =3D READ_ONCE(wsr->report_threshold); + + if (sc->priority =3D=3D DEF_PRIORITY) + return; + + if (!threshold) + return; + + if (!mutex_trylock(&wsr->page_age_lock)) + return; + + if (!wsr->page_age) { + mutex_unlock(&wsr->page_age_lock); + return; + } + + if (time_is_after_jiffies(wsr->page_age->timestamp + threshold)) { + mutex_unlock(&wsr->page_age_lock); + return; + } + + mutex_unlock(&wsr->page_age_lock); + notify_workingset(memcg, pgdat); +} +#endif /* CONFIG_WORKINGSET_REPORT */ + #else /* !CONFIG_LRU_GEN */ =20 static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_contro= l *sc) @@ -6191,6 +6234,9 @@ static void shrink_zones(struct zonelist *zonelist, s= truct scan_control *sc) if (zone->zone_pgdat =3D=3D last_pgdat) continue; last_pgdat =3D zone->zone_pgdat; + + if (!sc->proactive) + try_to_report_workingset(zone->zone_pgdat, sc); shrink_node(zone->zone_pgdat, sc); } =20 diff --git a/mm/workingset_report.c b/mm/workingset_report.c index fe553c0a653e..801ac8e5c1da 100644 --- a/mm/workingset_report.c +++ b/mm/workingset_report.c @@ -311,6 +311,33 @@ static struct wsr_state *kobj_to_wsr(struct kobject *k= obj) return &mem_cgroup_lruvec(NULL, kobj_to_pgdat(kobj))->wsr; } =20 +static ssize_t report_threshold_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + struct wsr_state *wsr =3D kobj_to_wsr(kobj); + unsigned int threshold =3D READ_ONCE(wsr->report_threshold); + + return sysfs_emit(buf, "%u\n", jiffies_to_msecs(threshold)); +} + +static ssize_t report_threshold_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t len) +{ + unsigned int threshold; + struct wsr_state *wsr =3D kobj_to_wsr(kobj); + + if (kstrtouint(buf, 0, &threshold)) + return -EINVAL; + + WRITE_ONCE(wsr->report_threshold, msecs_to_jiffies(threshold)); + + return len; +} + +static struct kobj_attribute report_threshold_attr =3D + __ATTR_RW(report_threshold); + static ssize_t refresh_interval_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -465,6 +492,7 @@ static ssize_t page_age_show(struct kobject *kobj, stru= ct kobj_attribute *attr, static struct kobj_attribute page_age_attr =3D __ATTR_RO(page_age); =20 static struct attribute *workingset_report_attrs[] =3D { + &report_threshold_attr.attr, &refresh_interval_attr.attr, &page_age_intervals_attr.attr, &page_age_attr.attr, @@ -486,8 +514,13 @@ void wsr_init_sysfs(struct node *node) =20 wsr =3D kobj_to_wsr(kobj); =20 - if (sysfs_create_group(kobj, &workingset_report_attr_group)) + if (sysfs_create_group(kobj, &workingset_report_attr_group)) { pr_warn("Workingset report failed to create sysfs files\n"); + return; + } + + wsr->page_age_sys_file =3D + kernfs_walk_and_get(kobj->sd, "workingset_report/page_age"); } EXPORT_SYMBOL_GPL(wsr_init_sysfs); =20 @@ -500,6 +533,14 @@ void wsr_remove_sysfs(struct node *node) return; =20 wsr =3D kobj_to_wsr(kobj); + kernfs_put(wsr->page_age_sys_file); sysfs_remove_group(kobj, &workingset_report_attr_group); } EXPORT_SYMBOL_GPL(wsr_remove_sysfs); + +void notify_workingset(struct mem_cgroup *memcg, struct pglist_data *pgdat) +{ + struct wsr_state *wsr =3D &mem_cgroup_lruvec(memcg, pgdat)->wsr; + + kernfs_notify(wsr->page_age_sys_file); +} --=20 2.46.0.76.ge559c4bf1a-goog