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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88734C433EF for ; Wed, 16 Mar 2022 13:35:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243060AbiCPNgO (ORCPT ); Wed, 16 Mar 2022 09:36:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241579AbiCPNgM (ORCPT ); Wed, 16 Mar 2022 09:36:12 -0400 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 519454704D for ; Wed, 16 Mar 2022 06:34:58 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id s8so3888674pfk.12 for ; Wed, 16 Mar 2022 06:34:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=0FFUC79IimSnK/DZVddYsmMD3YBmhcKxrgWlWwNvz/c=; b=mBW9zvH4keJLen3B6/V50s5wCVcTUC+Irf+5Y7w51p+/8+56fLNv/RW39CsmQcpW+F 5tTUnb3BW7VrdH7ry3kHBq0WxfNLtPFW/lmYip7YdAJuwnr6Vvo9JvDB3mC+y0LZ6dqf r1bf2gZTIs7A5eIXhxcwUtIP9e9GuOxHgUdebWY7atYRpw0YHLCPeekZVuxDdo8yHEaG iaXbuh69kf11ODVaY2TTo+Uitfw8eIsTpXweIzDTN5/Gc6teB9wcLrPWydio+yETIzcn a9cdEnBhSoDBQRPAJiQlObHMnvmk7/YfPvH+3yrV/j3JFxUXIepMZc4lttZ/ncHbAvvc D67w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=0FFUC79IimSnK/DZVddYsmMD3YBmhcKxrgWlWwNvz/c=; b=sfrHZxPn+sX4FPQK+uYImA2Zr8Kf3R10JxwxGGeMC5WwUQGoL3uHAxX/G36yNrrfXZ 9VtUmeWXMR4AqMCLN/dPRYeamoAjwRdLPU0FVKNTV1FW/B4BGhpzYFjY9/6fxYo6I4M2 Yvsejp+vqsUItkWlXMLeavLfDH03qMu+JrwYkyCAw0YWsH2eDJnGoMdLpYFxt2eEexb5 tN5Zpytv4TIUHtQNs0O6f/EvHoIiKSE8I4oN0UEJGEhPDrFOt3QM1fDpdVvItb8uibcT jnEeyHI/l5+qV4yJ/qKMWlZJkJTLmL2+18CTXF5eVDbUpUUqrIbVB5zi185uAM7dMnUN paBQ== X-Gm-Message-State: AOAM530KQBxOTd8bn05hBJawwyBHZARpB9BmXLql1YHONffo19Q192vf /ghOPHg12D3+vh7A1bC4Fo1yfrk4Kmw= X-Google-Smtp-Source: ABdhPJzjeRU4ZDJfzNUwpJfQG62LNcOzA29xh8uLuJ381O2a7qDTtKNuDD9aIVvl0cCOA4fH3FqczA== X-Received: by 2002:a05:6a00:1806:b0:4f6:f3e8:b3a0 with SMTP id y6-20020a056a00180600b004f6f3e8b3a0mr33976415pfa.43.1647437697719; Wed, 16 Mar 2022 06:34:57 -0700 (PDT) Received: from localhost.localdomain ([193.203.214.57]) by smtp.gmail.com with ESMTPSA id o7-20020a056a00214700b004c169d45699sm3108407pfk.184.2022.03.16.06.34.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Mar 2022 06:34:57 -0700 (PDT) From: cgel.zte@gmail.com X-Google-Original-From: yang.yang29@zte.com.cn To: bsingharora@gmail.com, akpm@linux-foundation.org Cc: yang.yang29@zte.com.cn, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH] delayacct: track delays from ksm cow Date: Wed, 16 Mar 2022 13:34:21 +0000 Message-Id: <20220316133420.2131707-1-yang.yang29@zte.com.cn> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yang Yang Delay accounting does not track the delay of ksm cow. When tasks have many ksm pages, it may spend a amount of time waiting for ksm cow. To get the impact of tasks in ksm cow, measure the delay when ksm cow happens. This could help users to decide whether to user ksm or not. Also update tools/accounting/getdelays.c: / # ./getdelays -dl -p 231 print delayacct stats ON listen forever PID 231 CPU count real total virtual total delay total delay average 6247 1859000000 2154070021 1674255063 0.268ms IO count delay total delay average 0 0 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 0 0 0ms KSM count delay total delay average 3635 271567604 0ms Signed-off-by: Yang Yang --- include/linux/delayacct.h | 28 ++++++++++++++++++++++++++++ include/uapi/linux/taskstats.h | 6 +++++- kernel/delayacct.c | 16 ++++++++++++++++ mm/memory.c | 25 ++++++++++++++++++++++--- tools/accounting/getdelays.c | 8 +++++++- 5 files changed, 78 insertions(+), 5 deletions(-) diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 6b16a6930a19..0fbe2cb25c23 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -45,9 +45,13 @@ struct task_delay_info { u64 compact_start; u64 compact_delay; /* wait for memory compact */ + u64 ksm_start; + u64 ksm_delay; /* wait for ksm cow */ + u32 freepages_count; /* total count of memory reclaim */ u32 thrashing_count; /* total count of thrash waits */ u32 compact_count; /* total count of memory compact */ + u32 ksm_count; /* total count of ksm cow */ }; #endif @@ -75,6 +79,8 @@ extern void __delayacct_swapin_start(void); extern void __delayacct_swapin_end(void); extern void __delayacct_compact_start(void); extern void __delayacct_compact_end(void); +extern void __delayacct_ksm_start(void); +extern void __delayacct_ksm_end(void); static inline void delayacct_tsk_init(struct task_struct *tsk) { @@ -191,6 +197,24 @@ static inline void delayacct_compact_end(void) __delayacct_compact_end(); } +static inline void delayacct_ksm_start(void) +{ + if (!static_branch_unlikely(&delayacct_key)) + return; + + if (current->delays) + __delayacct_ksm_start(); +} + +static inline void delayacct_ksm_end(void) +{ + if (!static_branch_unlikely(&delayacct_key)) + return; + + if (current->delays) + __delayacct_ksm_end(); +} + #else static inline void delayacct_init(void) {} @@ -225,6 +249,10 @@ static inline void delayacct_compact_start(void) {} static inline void delayacct_compact_end(void) {} +static inline void delayacct_ksm_start(void) +{} +static inline void delayacct_ksm_end(void) +{} #endif /* CONFIG_TASK_DELAY_ACCT */ diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h index 12327d32378f..a851c032dfb8 100644 --- a/include/uapi/linux/taskstats.h +++ b/include/uapi/linux/taskstats.h @@ -34,7 +34,7 @@ */ -#define TASKSTATS_VERSION 11 +#define TASKSTATS_VERSION 12 #define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN * in linux/sched.h */ @@ -176,6 +176,10 @@ struct taskstats { /* Delay waiting for memory compact */ __u64 compact_count; __u64 compact_delay_total; + + /* Delay waiting for ksm cow */ + __u64 ksm_count; + __u64 ksm_delay_total; }; diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 2c1e18f7c5cf..11accef0c2bd 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -177,11 +177,14 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp; tmp = d->compact_delay_total + tsk->delays->compact_delay; d->compact_delay_total = (tmp < d->compact_delay_total) ? 0 : tmp; + tmp = d->ksm_delay_total + tsk->delays->ksm_delay; + d->ksm_delay_total = (tmp < d->ksm_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; d->compact_count += tsk->delays->compact_count; + d->ksm_count += tsk->delays->ksm_count; raw_spin_unlock_irqrestore(&tsk->delays->lock, flags); return 0; @@ -249,3 +252,16 @@ void __delayacct_compact_end(void) ¤t->delays->compact_delay, ¤t->delays->compact_count); } + +void __delayacct_ksm_start(void) +{ + current->delays->ksm_start = local_clock(); +} + +void __delayacct_ksm_end(void) +{ + delayacct_end(¤t->delays->lock, + ¤t->delays->ksm_start, + ¤t->delays->ksm_delay, + ¤t->delays->ksm_count); +} diff --git a/mm/memory.c b/mm/memory.c index 4499cf09c21f..23dfc3b24d28 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3249,6 +3249,8 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; + vm_fault_t ret = 0; + bool delayacct = false; if (userfaultfd_pte_wp(vma, *vmf->pte)) { pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -3294,7 +3296,11 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) * * PageKsm() doesn't necessarily raise the page refcount. */ - if (PageKsm(page) || page_count(page) > 3) + if (PageKsm(page)) { + delayacct = true; + goto copy; + } + if (page_count(page) > 3) goto copy; if (!PageLRU(page)) /* @@ -3308,7 +3314,12 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) goto copy; if (PageSwapCache(page)) try_to_free_swap(page); - if (PageKsm(page) || page_count(page) != 1) { + if (PageKsm(page)) { + delayacct = true; + unlock_page(page); + goto copy; + } + if (page_count(page) != 1) { unlock_page(page); goto copy; } @@ -3328,10 +3339,18 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) /* * Ok, we need to copy. Oh, well.. */ + if (delayacct) + delayacct_ksm_start(); + get_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); - return wp_page_copy(vmf); + ret = wp_page_copy(vmf); + + if (delayacct) + delayacct_ksm_end(); + + return ret; } static void unmap_mapping_range_vma(struct vm_area_struct *vma, diff --git a/tools/accounting/getdelays.c b/tools/accounting/getdelays.c index 11e86739456d..3e77c9ff7fcf 100644 --- a/tools/accounting/getdelays.c +++ b/tools/accounting/getdelays.c @@ -207,6 +207,8 @@ static void print_delayacct(struct taskstats *t) "THRASHING%12s%15s%15s\n" " %15llu%15llu%15llums\n" "COMPACT %12s%15s%15s\n" + " %15llu%15llu%15llums\n" + "KSM %15s%15s%15s\n" " %15llu%15llu%15llums\n", "count", "real total", "virtual total", "delay total", "delay average", @@ -234,7 +236,11 @@ static void print_delayacct(struct taskstats *t) "count", "delay total", "delay average", (unsigned long long)t->compact_count, (unsigned long long)t->compact_delay_total, - average_ms(t->compact_delay_total, t->compact_count)); + average_ms(t->compact_delay_total, t->compact_count), + "count", "delay total", "delay average", + (unsigned long long)t->ksm_count, + (unsigned long long)t->ksm_delay_total, + average_ms(t->ksm_delay_total, t->ksm_count)); } static void task_context_switch_counts(struct taskstats *t) -- 2.25.1