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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 E6A95C433DF for ; Thu, 4 Jun 2020 04:02:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ADBAD2072E for ; Thu, 4 Jun 2020 04:02:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADBAD2072E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 31028280009; Thu, 4 Jun 2020 00:02:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2C0A08000E; Thu, 4 Jun 2020 00:02:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1FD1A280009; Thu, 4 Jun 2020 00:02:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id 04CEC8000E for ; Thu, 4 Jun 2020 00:02:05 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C07A6180AD804 for ; Thu, 4 Jun 2020 04:02:04 +0000 (UTC) X-FDA: 76890181368.02.house18_2f2f5dffef328 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id A42B31277 for ; Thu, 4 Jun 2020 04:02:04 +0000 (UTC) X-HE-Tag: house18_2f2f5dffef328 X-Filterd-Recvd-Size: 6499 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Thu, 4 Jun 2020 04:02:04 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 06F2D55D; Wed, 3 Jun 2020 21:02:03 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.78.173]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BCBF03F6CF; Wed, 3 Jun 2020 21:01:59 -0700 (PDT) From: Anshuman Khandual To: linux-mm@kvack.org Cc: hughd@google.com, daniel.m.jordan@oracle.com, willy@infradead.org, Anshuman Khandual , Naoya Horiguchi , Zi Yan , John Hubbard , Andrew Morton , linux-kernel@vger.kernel.org Subject: [PATCH V2] mm/vmstat: Add events for THP migration without split Date: Thu, 4 Jun 2020 09:30:45 +0530 Message-Id: <1591243245-23052-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 X-Rspamd-Queue-Id: A42B31277 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: Add the following new VM events which will help in validating THP migration without split. Statistics reported through these new events will help in performance debugging. 1. THP_MIGRATION_SUCCESS 2. THP_MIGRATION_FAILURE THP_MIGRATION_FAILURE in particular represents an event when a THP could not be migrated as a single entity following an allocation failure and ended up getting split into constituent normal pages before being retried. This event, along with PGMIGRATE_SUCCESS and PGMIGRATE_FAIL will help in quantifying and analyzing THP migration events including both success and failure cases. Cc: Naoya Horiguchi Cc: Zi Yan Cc: John Hubbard Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org [hughd: fixed oops on NULL newpage] Signed-off-by: Anshuman Khandual --- Changes in V2: - Dropped PMD reference both from code and commit message per Matthew - Added documentation and updated the commit message per Daniel Changes in V1: (https://patchwork.kernel.org/patch/11564497/) - Changed function name as thp_pmd_migration_success() per John - Folded in a fix (https://patchwork.kernel.org/patch/11563009/) from Hugh Changes in RFC V2: (https://patchwork.kernel.org/patch/11554861/) - Decopupled and renamed VM events from their implementation per Zi and John - Added THP_PMD_MIGRATION_FAILURE VM event upon allocation failure and split Changes in RFC V1: (https://patchwork.kernel.org/patch/11542055/) Documentation/vm/page_migration.rst | 15 +++++++++++++++ include/linux/vm_event_item.h | 4 ++++ mm/migrate.c | 23 +++++++++++++++++++++++ mm/vmstat.c | 4 ++++ 4 files changed, 46 insertions(+) diff --git a/Documentation/vm/page_migration.rst b/Documentation/vm/page_migration.rst index 1d6cd7db4e43..67e9b067fed7 100644 --- a/Documentation/vm/page_migration.rst +++ b/Documentation/vm/page_migration.rst @@ -253,5 +253,20 @@ which are function pointers of struct address_space_operations. PG_isolated is alias with PG_reclaim flag so driver shouldn't use the flag for own purpose. +Quantifying Migration +===================== +Following events can be used to quantify page migration. + +- PGMIGRATE_SUCCESS +- PGMIGRATE_FAIL +- THP_MIGRATION_SUCCESS +- THP_MIGRATION_FAILURE + +THP_MIGRATION_FAILURE in particular represents an event when a THP could not be +migrated as a single entity following an allocation failure and ended up getting +split into constituent normal pages before being retried. This event, along with +PGMIGRATE_SUCCESS and PGMIGRATE_FAIL will help in quantifying and analyzing THP +migration events including both success and failure cases. + Christoph Lameter, May 8, 2006. Minchan Kim, Mar 28, 2016. diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index ffef0f279747..6459265461df 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -91,6 +91,10 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, THP_ZERO_PAGE_ALLOC_FAILED, THP_SWPOUT, THP_SWPOUT_FALLBACK, +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION + THP_MIGRATION_SUCCESS, + THP_MIGRATION_FAILURE, +#endif #endif #ifdef CONFIG_MEMORY_BALLOON BALLOON_INFLATE, diff --git a/mm/migrate.c b/mm/migrate.c index 7160c1556f79..0bb1dbb891bb 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1170,6 +1170,20 @@ static int __unmap_and_move(struct page *page, struct page *newpage, #define ICE_noinline #endif +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +static inline void thp_migration_success(bool success) +{ + if (success) + count_vm_event(THP_MIGRATION_SUCCESS); + else + count_vm_event(THP_MIGRATION_FAILURE); +} +#else +static inline void thp_migration_success(bool success) +{ +} +#endif + /* * Obtain the lock on page, remove all ptes and migrate the page * to the newly allocated page in newpage. @@ -1232,6 +1246,14 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page, * we want to retry. */ if (rc == MIGRATEPAGE_SUCCESS) { + /* + * When the page to be migrated has been freed from under + * us, that is considered a MIGRATEPAGE_SUCCESS, but no + * newpage has been allocated. It should not be counted + * as a successful THP migration. + */ + if (newpage && PageTransHuge(newpage)) + thp_migration_success(true); put_page(page); if (reason == MR_MEMORY_FAILURE) { /* @@ -1474,6 +1496,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, unlock_page(page); if (!rc) { list_safe_reset_next(page, page2, lru); + thp_migration_success(false); goto retry; } } diff --git a/mm/vmstat.c b/mm/vmstat.c index 96d21a792b57..4ce1ab2e9704 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1274,6 +1274,10 @@ const char * const vmstat_text[] = { "thp_zero_page_alloc_failed", "thp_swpout", "thp_swpout_fallback", +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION + "thp_migration_success", + "thp_migration_failure", +#endif #endif #ifdef CONFIG_MEMORY_BALLOON "balloon_inflate", -- 2.20.1