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 X-Spam-Level: X-Spam-Status: No, score=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 359D8C43334 for ; Tue, 28 Aug 2018 17:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE2E820897 for ; Tue, 28 Aug 2018 17:23:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="rv6b+n5M" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE2E820897 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cmpxchg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727562AbeH1VQH (ORCPT ); Tue, 28 Aug 2018 17:16:07 -0400 Received: from mail-yb0-f194.google.com ([209.85.213.194]:41977 "EHLO mail-yb0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727518AbeH1VQF (ORCPT ); Tue, 28 Aug 2018 17:16:05 -0400 Received: by mail-yb0-f194.google.com with SMTP id z3-v6so894391ybm.8 for ; Tue, 28 Aug 2018 10:23:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=rYqRJD/Nn/mjyDEIlHij4Nq2ZQJyQDLbJcRnxwRjma8=; b=rv6b+n5M5/s6153mcQJP8vb8uQTvc0ZkerEzMVY/d84AUjep2LMXmRZe1FWs1qjyXF s0y0Ha0UgpGEJTASxmj542o50DJGU1z1eH3au+YA4fExeolwZJJ5hJBuH4Tau6DKmtxx SB/JZUuFL9anXIHerqONyisv6lsGmSnn8vJfn9deTIyTgidwM+3hGJm/z0JA81qWhsLf 4dQgA3HjMEuD/3l6gkLH4TFX8U1/eJUq+MNxqI91DS/OI9iF6jUKjBz/OpVN5l1ziDrn Kfirj7wk4y8q/udRMCGkLXNyJgUVZKh3tY/O/DLXkJkib73qxfeUKXRcAxGoSLAH2RbV hRgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=rYqRJD/Nn/mjyDEIlHij4Nq2ZQJyQDLbJcRnxwRjma8=; b=V3q36fbXv1tgUH+HU62cGSqHT2c/viwM96U9A6gXaiZSxWLk77xfZ8Eu4iwJUf8MRw TJHn3X6RUyomRzb0nqpmHMhHHe+kkiJPgyJbZAEP/tGs2o1wyIC6oWNSmecmBoId7PpV 61eWtmWC0MqfQyN1PVuD9sCOK1HpOBm9LZZ7pMtOsnuoE1/RjnYsZ92T14H7dgvJWOgV xXQlTMkhfqS45AT+oxbD06V+yj6DVcCFYCyeSjTNIwh/fcQdgL1BCVE9stcHCSTJZTiM yV3cawicDDDME0wSyykR7MBGlwYXrBrsN/p2mmODdTTLOoxoVig4MYkDXCs7HphfWYvH vf+g== X-Gm-Message-State: APzg51Dhnu22PrQe2TmBlOV0POBvhbILBHOL9qFD0fhLJCe25GC5+e0W gywsYm6R3QpTjJD34g/NNw+pfg== X-Google-Smtp-Source: ANB0VdYcmdWXjf09BCqTnjZc3KIcNh2/avH9YSJ2USJIxkxAPyEpIv0mY9KySK7FjbOWOTftW3VZAQ== X-Received: by 2002:a25:103:: with SMTP id 3-v6mr1411840ybb.421.1535477005285; Tue, 28 Aug 2018 10:23:25 -0700 (PDT) Received: from localhost ([2620:10d:c091:200::1:de86]) by smtp.gmail.com with ESMTPSA id c126-v6sm1609448ywa.104.2018.08.28.10.23.23 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 28 Aug 2018 10:23:24 -0700 (PDT) From: Johannes Weiner To: Ingo Molnar , Peter Zijlstra , Andrew Morton , Linus Torvalds Cc: Tejun Heo , Suren Baghdasaryan , Daniel Drake , Vinayak Menon , Christopher Lameter , Peter Enderborg , Shakeel Butt , Mike Galbraith , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 3/9] delayacct: track delays from thrashing cache pages Date: Tue, 28 Aug 2018 13:22:52 -0400 Message-Id: <20180828172258.3185-4-hannes@cmpxchg.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180828172258.3185-1-hannes@cmpxchg.org> References: <20180828172258.3185-1-hannes@cmpxchg.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Delay accounting already measures the time a task spends in direct reclaim and waiting for swapin, but in low memory situations tasks spend can spend a significant amount of their time waiting on thrashing page cache. This isn't tracked right now. To know the full impact of memory contention on an individual task, measure the delay when waiting for a recently evicted active cache page to read back into memory. Also update tools/accounting/getdelays.c: [hannes@computer accounting]$ sudo ./getdelays -d -p 1 print delayacct stats ON PID 1 CPU count real total virtual total delay total delay average 50318 745000000 847346785 400533713 0.008ms IO count delay total delay average 435 122601218 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 0 0 0ms THRASHING count delay total delay average 19 12621439 0ms Signed-off-by: Johannes Weiner --- include/linux/delayacct.h | 23 +++++++++++++++++++++++ include/uapi/linux/taskstats.h | 6 +++++- kernel/delayacct.c | 15 +++++++++++++++ mm/filemap.c | 11 +++++++++++ tools/accounting/getdelays.c | 8 +++++++- 5 files changed, 61 insertions(+), 2 deletions(-) diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 31c865d1842e..577d1b25fccd 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -57,7 +57,12 @@ struct task_delay_info { u64 freepages_start; u64 freepages_delay; /* wait for memory reclaim */ + + u64 thrashing_start; + u64 thrashing_delay; /* wait for thrashing page */ + u32 freepages_count; /* total count of memory reclaim */ + u32 thrashing_count; /* total count of thrash waits */ }; #endif @@ -76,6 +81,8 @@ extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); extern __u64 __delayacct_blkio_ticks(struct task_struct *); extern void __delayacct_freepages_start(void); extern void __delayacct_freepages_end(void); +extern void __delayacct_thrashing_start(void); +extern void __delayacct_thrashing_end(void); static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) { @@ -156,6 +163,18 @@ static inline void delayacct_freepages_end(void) __delayacct_freepages_end(); } +static inline void delayacct_thrashing_start(void) +{ + if (current->delays) + __delayacct_thrashing_start(); +} + +static inline void delayacct_thrashing_end(void) +{ + if (current->delays) + __delayacct_thrashing_end(); +} + #else static inline void delayacct_set_flag(int flag) {} @@ -182,6 +201,10 @@ static inline void delayacct_freepages_start(void) {} static inline void delayacct_freepages_end(void) {} +static inline void delayacct_thrashing_start(void) +{} +static inline void delayacct_thrashing_end(void) +{} #endif /* CONFIG_TASK_DELAY_ACCT */ diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h index b7aa7bb2349f..5e8ca16a9079 100644 --- a/include/uapi/linux/taskstats.h +++ b/include/uapi/linux/taskstats.h @@ -34,7 +34,7 @@ */ -#define TASKSTATS_VERSION 8 +#define TASKSTATS_VERSION 9 #define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN * in linux/sched.h */ @@ -164,6 +164,10 @@ struct taskstats { /* Delay waiting for memory reclaim */ __u64 freepages_count; __u64 freepages_delay_total; + + /* Delay waiting for thrashing page */ + __u64 thrashing_count; + __u64 thrashing_delay_total; }; diff --git a/kernel/delayacct.c b/kernel/delayacct.c index ca8ac2824f0b..2a12b988c717 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -135,9 +135,12 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; tmp = d->freepages_delay_total + tsk->delays->freepages_delay; d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp; + tmp = d->thrashing_delay_total + tsk->delays->thrashing_delay; + d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp; d->blkio_count += tsk->delays->blkio_count; d->swapin_count += tsk->delays->swapin_count; d->freepages_count += tsk->delays->freepages_count; + d->thrashing_count += tsk->delays->thrashing_count; raw_spin_unlock_irqrestore(&tsk->delays->lock, flags); return 0; @@ -169,3 +172,15 @@ void __delayacct_freepages_end(void) ¤t->delays->freepages_count); } +void __delayacct_thrashing_start(void) +{ + current->delays->thrashing_start = ktime_get_ns(); +} + +void __delayacct_thrashing_end(void) +{ + delayacct_end(¤t->delays->lock, + ¤t->delays->thrashing_start, + ¤t->delays->thrashing_delay, + ¤t->delays->thrashing_count); +} diff --git a/mm/filemap.c b/mm/filemap.c index 5e53424d9097..ca895ebe43ac 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "internal.h" #define CREATE_TRACE_POINTS @@ -1073,8 +1074,15 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, { struct wait_page_queue wait_page; wait_queue_entry_t *wait = &wait_page.wait; + bool thrashing = false; int ret = 0; + if (bit_nr == PG_locked && !PageSwapBacked(page) && + !PageUptodate(page) && PageWorkingset(page)) { + delayacct_thrashing_start(); + thrashing = true; + } + init_wait(wait); wait->flags = lock ? WQ_FLAG_EXCLUSIVE : 0; wait->func = wake_page_function; @@ -1113,6 +1121,9 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, finish_wait(q, wait); + if (thrashing) + delayacct_thrashing_end(); + /* * A signal could leave PageWaiters set. Clearing it here if * !waitqueue_active would be possible (by open-coding finish_wait), diff --git a/tools/accounting/getdelays.c b/tools/accounting/getdelays.c index 9f420d98b5fb..8cb504d30384 100644 --- a/tools/accounting/getdelays.c +++ b/tools/accounting/getdelays.c @@ -203,6 +203,8 @@ static void print_delayacct(struct taskstats *t) "SWAP %15s%15s%15s\n" " %15llu%15llu%15llums\n" "RECLAIM %12s%15s%15s\n" + " %15llu%15llu%15llums\n" + "THRASHING%12s%15s%15s\n" " %15llu%15llu%15llums\n", "count", "real total", "virtual total", "delay total", "delay average", @@ -222,7 +224,11 @@ static void print_delayacct(struct taskstats *t) "count", "delay total", "delay average", (unsigned long long)t->freepages_count, (unsigned long long)t->freepages_delay_total, - average_ms(t->freepages_delay_total, t->freepages_count)); + average_ms(t->freepages_delay_total, t->freepages_count), + "count", "delay total", "delay average", + (unsigned long long)t->thrashing_count, + (unsigned long long)t->thrashing_delay_total, + average_ms(t->thrashing_delay_total, t->thrashing_count)); } static void task_context_switch_counts(struct taskstats *t) -- 2.18.0