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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4B6AC433FE for ; Thu, 4 Nov 2021 09:17:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AC46611C4 for ; Thu, 4 Nov 2021 09:17:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230494AbhKDJTi (ORCPT ); Thu, 4 Nov 2021 05:19:38 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:34114 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230335AbhKDJTg (ORCPT ); Thu, 4 Nov 2021 05:19:36 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 7BAFE218B8; Thu, 4 Nov 2021 09:16:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1636017418; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cnmN7XsFGspLlK0PAiomJNKlrkssbDZe/ikrw5j15PU=; b=aUsnRBMHd0qPSKQxreO1VhHURoINKN6BAwu1IYILWzDrlsol7R+1NXtFSW4wridF2a798m 7R84rQn1F4H+PKYjyirs+Begx2H7cJO/cor0SGQDGfuLKRYkRU6EhWjma39EH+iCriWBvX BTdfPYvCCa6JgxjWP8GNZdnl7NLwAm0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1636017418; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cnmN7XsFGspLlK0PAiomJNKlrkssbDZe/ikrw5j15PU=; b=0wp3IQzm4yDADf4Y84tG1P0SzsfZQrmqQc83vwCGDpo8pE4HrPCIDqSj7SrFu/KWKbN2Ln iDgxlyB+SVnpTdBg== Received: from suse.de (unknown [10.163.32.246]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id A0D9C2C157; Thu, 4 Nov 2021 09:16:56 +0000 (UTC) Date: Thu, 4 Nov 2021 09:16:54 +0000 From: Mel Gorman To: Jimmy Shiu Cc: mingo@redhat.com, joaodias@google.com, wvw@google.com, Minchan Kim , Will McVicker , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Daniel Bristot de Oliveira , Andrew Morton , "Matthew Wilcox (Oracle)" , David Howells , Vlastimil Babka , William Kucharski , "Kirill A. Shutemov" , Andreas Gruenbacher , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] SCHED: attribute page lock and waitqueue functions as sched Message-ID: <20211104091654.GV3891@suse.de> References: <20211103184708.1778294-1-jimmyshiu@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20211103184708.1778294-1-jimmyshiu@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 04, 2021 at 02:47:03AM +0800, Jimmy Shiu wrote: > trace_sched_blocked_trace in CFS is really useful for debugging via > trace because it tell where the process was stuck on callstack. > > For example, > <...>-6143 ( 6136) [005] d..2 50.278987: sched_blocked_reason: pid=6136 iowait=0 caller=SyS_mprotect+0x88/0x208 > <...>-6136 ( 6136) [005] d..2 50.278990: sched_blocked_reason: pid=6142 iowait=0 caller=do_page_fault+0x1f4/0x3b0 > <...>-6142 ( 6136) [006] d..2 50.278996: sched_blocked_reason: pid=6144 iowait=0 caller=SyS_prctl+0x52c/0xb58 > <...>-6144 ( 6136) [006] d..2 50.279007: sched_blocked_reason: pid=6136 iowait=0 caller=vm_mmap_pgoff+0x74/0x104 > > However, sometime it gives pointless information like this. > RenderThread-2322 ( 1805) [006] d.s3 50.319046: sched_blocked_reason: pid=6136 iowait=1 caller=__lock_page_killable+0x17c/0x220 > logd.writer-594 ( 587) [002] d.s3 50.334011: sched_blocked_reason: pid=6126 iowait=1 caller=wait_on_page_bit+0x194/0x208 > kworker/u16:13-333 ( 333) [007] d.s4 50.343161: sched_blocked_reason: pid=6136 iowait=1 caller=__lock_page_killable+0x17c/0x220 > /me peers at coffee Maybe I'm blind but aside from Matthew's concerns, this appears to rely on an Android patch that is not upstream https://android.googlesource.com/kernel/msm/+/c9f00aa0e25e397533c198a0fcf6246715f99a7b%5E!/ -- Mel Gorman SUSE Labs