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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 B483DC433E0 for ; Wed, 3 Feb 2021 18:01:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6669D64F51 for ; Wed, 3 Feb 2021 18:01:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232750AbhBCSB0 (ORCPT ); Wed, 3 Feb 2021 13:01:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232645AbhBCR7t (ORCPT ); Wed, 3 Feb 2021 12:59:49 -0500 Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EEFFC061573 for ; Wed, 3 Feb 2021 09:59:08 -0800 (PST) Received: by mail-wr1-x433.google.com with SMTP id v15so254096wrx.4 for ; Wed, 03 Feb 2021 09:59:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=bTjQz8Dnxjan8mjD0lOv8/iSRasIU/sl1+6PEFzSC+s=; b=S5C59m6h1Oc8GkHH2GhqYZkWHmJW37xp9kEpauQgpbfeh+E4cIsbyhOmzSYomsDe4m g1UMjkezFIEuhJv5QpSzqi+1tTDr+gaE4CLbXrW3haS8vj2PfqElxjdKnh7kz1F3RTaI ncOwqhMELit/5LxlPYT1yEAqyIDJpuQjaJyhPSCJ2gn526sM13LIlbKDBKMMi1pTDsG/ R0SxNjvCq4cVebnoY/A0//sVfhVQB/SR+zKu3LM1DECVMCOceHqy1IAVOvwyVjsF2e7t vZ63QAyeJIuzluKW4XCL2w1amZ9KcaHsB9rOLZQwKt10hm9y2Gfhblsj78htqHLOPrDo WMZQ== 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:mime-version :content-transfer-encoding; bh=bTjQz8Dnxjan8mjD0lOv8/iSRasIU/sl1+6PEFzSC+s=; b=Ft5ruw8aDzYvHsa1T1TC09npjD9alqcPOM1UcnuZkAKClp1PLEqCfLBM9Yu1knxCGs FMzPt/1r7javIR9QbMeIgfiUEdzt4D45Ge+jcvSpt7aTrLUAPO8OuOOrXo/IwD0w6QK6 +yPSOeYHhnYtNEvEgXg0pRSTSuT3RZbvrobBLCjNZ/zSeJIdF6P7pdzs/8xZnR87M1Pt RxLzXepuOZNhaHwZSgMbHQqWUqWxMu9zUTYwuQ346KJOZOQcw1FncfI+UIPM+WQbpySa RpFzfB+aevz5Be6q+jbBAvwdUzT7AwdZGQJTZXtW2jV7Hz9+pIS05Izxhjg0QFCXs2q4 E/Gg== X-Gm-Message-State: AOAM532JKSXFZ2OhCvV3lT6XJveRBFwf1R9aAA6lWd9/PSLri6BCL5P8 IQoRApMtVmQOZ1g8fexKZ4o79A== X-Google-Smtp-Source: ABdhPJxNrJ1EWAksIvhKUYtOPTUyO7RzR8zWAGRNz/pNQUsNnFiTKb+WjhMBxzuVsyevVnthpGFcGw== X-Received: by 2002:adf:fd52:: with SMTP id h18mr4911860wrs.295.1612375147252; Wed, 03 Feb 2021 09:59:07 -0800 (PST) Received: from localhost.localdomain ([212.45.67.2]) by smtp.googlemail.com with ESMTPSA id m10sm4741832wro.7.2021.02.03.09.59.05 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Feb 2021 09:59:06 -0800 (PST) From: Georgi Djakov To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: vbabka@suse.cz, corbet@lwn.net, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, georgi.djakov@linaro.org Subject: [PATCH v2] mm/page_owner: Record the timestamp of all pages during free Date: Wed, 3 Feb 2021 19:59:05 +0200 Message-Id: <20210203175905.12267-1-georgi.djakov@linaro.org> X-Mailer: git-send-email 2.29.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Collect the time when each allocation is freed, to help with memory analysis with kdump/ramdump. Add the timestamp also in the page_owner debugfs file and print it in dump_page(). Having another timestamp when we free the page helps for debugging page migration issues. For example both alloc and free timestamps being the same can gave hints that there is an issue with migrating memory, as opposed to a page just being dropped during migration. Signed-off-by: Georgi Djakov --- v2: * Don't reset the time of previous free when page is reallocated. (Vlastimil) * Add the timestamp in the page_owner file and dump_page(). (Vlastimil) v1: https://lore.kernel.org/r/20210129234548.10054-1-georgi.djakov@linaro.org Documentation/vm/page_owner.rst | 2 +- mm/page_owner.c | 12 ++++++++---- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/Documentation/vm/page_owner.rst b/Documentation/vm/page_owner.rst index 4e67c2e9bbed..2175465c9bf2 100644 --- a/Documentation/vm/page_owner.rst +++ b/Documentation/vm/page_owner.rst @@ -47,7 +47,7 @@ size change due to this facility. text data bss dec hex filename 48800 2445 644 51889 cab1 mm/page_alloc.o - 6574 108 29 6711 1a37 mm/page_owner.o + 6662 108 29 6799 1a8f mm/page_owner.o 1025 8 8 1041 411 mm/page_ext.o Although, roughly, 8 KB code is added in total, page_alloc.o increase by diff --git a/mm/page_owner.c b/mm/page_owner.c index d15c7c4994f5..9ceae81ba7b8 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -27,6 +27,7 @@ struct page_owner { depot_stack_handle_t handle; depot_stack_handle_t free_handle; u64 ts_nsec; + u64 free_ts_nsec; pid_t pid; }; @@ -148,6 +149,7 @@ void __reset_page_owner(struct page *page, unsigned int order) struct page_ext *page_ext; depot_stack_handle_t handle = 0; struct page_owner *page_owner; + u64 free_ts_nsec = local_clock(); handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); @@ -158,6 +160,7 @@ void __reset_page_owner(struct page *page, unsigned int order) __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); page_owner = get_page_owner(page_ext); page_owner->free_handle = handle; + page_owner->free_ts_nsec = free_ts_nsec; page_ext = page_ext_next(page_ext); } } @@ -243,6 +246,7 @@ void __copy_page_owner(struct page *oldpage, struct page *newpage) new_page_owner->handle = old_page_owner->handle; new_page_owner->pid = old_page_owner->pid; new_page_owner->ts_nsec = old_page_owner->ts_nsec; + new_page_owner->free_ts_nsec = old_page_owner->ts_nsec; /* * We don't clear the bit on the oldpage as it's going to be freed @@ -356,10 +360,10 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, return -ENOMEM; ret = snprintf(kbuf, count, - "Page allocated via order %u, mask %#x(%pGg), pid %d, ts %llu ns\n", + "Page allocated via order %u, mask %#x(%pGg), pid %d, ts %llu ns, free_ts %llu ns\n", page_owner->order, page_owner->gfp_mask, &page_owner->gfp_mask, page_owner->pid, - page_owner->ts_nsec); + page_owner->ts_nsec, page_owner->free_ts_nsec); if (ret >= count) goto err; @@ -435,9 +439,9 @@ void __dump_page_owner(struct page *page) else pr_alert("page_owner tracks the page as freed\n"); - pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, ts %llu\n", + pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, ts %llu, free_ts %llu\n", page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask, - page_owner->pid, page_owner->ts_nsec); + page_owner->pid, page_owner->ts_nsec, page_owner->free_ts_nsec); handle = READ_ONCE(page_owner->handle); if (!handle) {