From patchwork Fri Mar 25 01:09:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12791113 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EFD4C433EF for ; Fri, 25 Mar 2022 01:09:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0F4BF8D0008; Thu, 24 Mar 2022 21:09:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 07D706B0078; Thu, 24 Mar 2022 21:09:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E87A38D0008; Thu, 24 Mar 2022 21:09:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0084.hostedemail.com [216.40.44.84]) by kanga.kvack.org (Postfix) with ESMTP id D96A36B0071 for ; Thu, 24 Mar 2022 21:09:16 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 9C6E4A32D6 for ; Fri, 25 Mar 2022 01:09:16 +0000 (UTC) X-FDA: 79281125112.23.9712CF7 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf25.hostedemail.com (Postfix) with ESMTP id 27E01A0036 for ; Fri, 25 Mar 2022 01:09:15 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8CD1F61842; Fri, 25 Mar 2022 01:09:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C606CC340EE; Fri, 25 Mar 2022 01:09:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648170554; bh=T/QhIXGZA5VSUF/4RnuDzp+8eXKhoSwVd9XJvRG7tso=; h=Date:To:From:In-Reply-To:Subject:From; b=Y+vgRHansBpnaZ0EaZVDPlHe5MmpPBPM/JSpKeUAbDMqG/ff8MLJb0L9avL0SpnsO f6PAl1URnClT302mjGz54k65x90BzEH3FNRXZakocjXV4hLsX9cFEr6Tio0xe2ksnp Bxjbv4m7Lafj36O0+eiM3tRzuxM1+9cgoprJdgOw= Date: Thu, 24 Mar 2022 18:09:14 -0700 To: longman@redhat.com,aquini@redhat.com,caoyixuan2019@email.szu.edu.cn,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220324180758.96b1ac7e17675d6bc474485e@linux-foundation.org> Subject: [patch 013/114] mm/page_owner.c: record tgid Message-Id: <20220325010914.C606CC340EE@smtp.kernel.org> X-Rspam-User: X-Stat-Signature: kz3ospda87b5m9cqobhcs7ybn398f1c9 Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=Y+vgRHan; spf=pass (imf25.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 27E01A0036 X-HE-Tag: 1648170555-932856 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: From: Yixuan Cao Subject: mm/page_owner.c: record tgid In a single-threaded process, the pid in kernel task_struct is the same as the tgid, which can mark the process of page allocation. But in a multithreaded process, only the task_struct of the thread leader has the same pid as tgid, and the pids of other threads are different from tgid. Therefore, tgid is recorded to provide effective information for debugging and data statistics of multithreaded programs. This can also be achieved by observing the task name (executable file name) for a specific process. However, when the same program is started multiple times, the task name is the same and the tgid is different. Therefore, in the debugging of multi-threaded programs, combined with the task name and tgid, more accurate runtime information of a certain run of the program can be obtained. Link: https://lkml.kernel.org/r/20220219180450.2399-1-caoyixuan2019@email.szu.edu.cn Signed-off-by: Yixuan Cao Cc: Waiman Long Cc: Rafael Aquini Signed-off-by: Andrew Morton --- mm/page_owner.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) --- a/mm/page_owner.c~mm-page_ownerc-record-tgid +++ a/mm/page_owner.c @@ -31,6 +31,7 @@ struct page_owner { u64 free_ts_nsec; char comm[TASK_COMM_LEN]; pid_t pid; + pid_t tgid; }; static bool page_owner_enabled = false; @@ -165,6 +166,7 @@ static inline void __set_page_owner_hand page_owner->gfp_mask = gfp_mask; page_owner->last_migrate_reason = -1; page_owner->pid = current->pid; + page_owner->tgid = current->tgid; page_owner->ts_nsec = local_clock(); strlcpy(page_owner->comm, current->comm, sizeof(page_owner->comm)); @@ -233,6 +235,7 @@ void __folio_copy_owner(struct folio *ne old_page_owner->last_migrate_reason; new_page_owner->handle = old_page_owner->handle; new_page_owner->pid = old_page_owner->pid; + new_page_owner->tgid = old_page_owner->tgid; new_page_owner->ts_nsec = old_page_owner->ts_nsec; new_page_owner->free_ts_nsec = old_page_owner->ts_nsec; strcpy(new_page_owner->comm, old_page_owner->comm); @@ -383,11 +386,11 @@ print_page_owner(char __user *buf, size_ return -ENOMEM; ret = scnprintf(kbuf, count, - "Page allocated via order %u, mask %#x(%pGg), pid %d (%s), ts %llu ns, free_ts %llu ns\n", + "Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns, free_ts %llu ns\n", page_owner->order, page_owner->gfp_mask, &page_owner->gfp_mask, page_owner->pid, - page_owner->comm, page_owner->ts_nsec, - page_owner->free_ts_nsec); + page_owner->tgid, page_owner->comm, + page_owner->ts_nsec, page_owner->free_ts_nsec); /* Print information relevant to grouping pages by mobility */ pageblock_mt = get_pageblock_migratetype(page); @@ -454,10 +457,10 @@ void __dump_page_owner(const struct 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 (%s), ts %llu, free_ts %llu\n", + pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu, free_ts %llu\n", page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask, - page_owner->pid, page_owner->comm, page_owner->ts_nsec, - page_owner->free_ts_nsec); + page_owner->pid, page_owner->tgid, page_owner->comm, + page_owner->ts_nsec, page_owner->free_ts_nsec); handle = READ_ONCE(page_owner->handle); if (!handle) @@ -669,3 +672,4 @@ static int __init pageowner_init(void) return 0; } late_initcall(pageowner_init) +