From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-101.freemail.mail.aliyun.com (out30-101.freemail.mail.aliyun.com [115.124.30.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 249BD1A01B9 for ; Tue, 3 Dec 2024 08:15:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733213717; cv=none; b=ARqeXCOGKhjWtElX2tLYZBZlHnERTxGJElftNmYv4a9kg2hxxauqeJmwhVg7iFhjxjHz4+QHuvYqBn5kJ16V8Xq1Cqr/BiiKeCuD4EECPotap8hIgaNi1127EUYGbnqYcW2sYmpjuUi/hwdz8yC3xc493PpmJTwd6ZpT4CbMdJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733213717; c=relaxed/simple; bh=ZiLk7GgWvmZilORth65y8636sc7UGfmaJFiqtnWLVZE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KVtc5eVcI4/b7UPu2kJmGhvpdkMv6QuECO1ugA3p33oprTIYQZB6dlTY6fRMvvW7lxFlaSSciPHOcWXCKNkOzSoEFI74BBTJOEbWvdw6wkNlq1u2iQNR22CxJchLeYtkdsIQ+FLjxNPtXUyW8cZoh8Rye0rxjRiQiVdmxvsyQFQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=aHtMFiHE; arc=none smtp.client-ip=115.124.30.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="aHtMFiHE" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1733213706; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=P9bXSc8Mw7fyXPHQ8KEsd7SMB95kevoVh98GxRCDL0w=; b=aHtMFiHEbFDhGu1ihTWcEnnXR3Z2oQIYqsF7Z9J0LXbc8ln0+qlXss/Zb5snHJR3aCtijv/+mruE11RtNfSyIimXQacaLo+pURKz0m/pxy1gNL5Zex5tsbz82iqh9fAsn7PPxPJSfEVysLR8oyTZThYo3fSn8C05mfUXkQin398= Received: from 30.221.129.129(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0WKm.qCN_1733213705 cluster:ay36) by smtp.aliyun-inc.com; Tue, 03 Dec 2024 16:15:05 +0800 Message-ID: <0584d334-4e75-4d35-be33-03d6ff7a0aba@linux.alibaba.com> Date: Tue, 3 Dec 2024 16:15:05 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] erofs: fix PSI memstall accounting To: Max Kellermann Cc: linux-erofs@lists.ozlabs.org, LKML References: <20241127085236.3538334-1-hsiangkao@linux.alibaba.com> From: Gao Xiang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2024/12/3 16:02, Max Kellermann via Linux-erofs wrote: > On Tue, Dec 3, 2024 at 2:42 AM Gao Xiang wrote: >> I think at least this patch resolves a recent regression, >> I guess we'd better to address it first. > > Certainly your patch is an improvement, but maybe this just wasn't the > bug I was experiencing. > >> As for your reports, I think we might need more information >> about this, since I don't find more clues from the EROFS >> codebase itself. > > What kind of information do you need? I posted some high-level > information about my setup here: > https://lore.kernel.org/lkml/CAKPOu+-_X9cc723v_f_BW4CwfHJe_mi=+cbUBP2tZO-kEcyoMA@mail.gmail.com/ > What else do you want to know? > This triggers pretty often now - can we improve Suren's patch to > record and dump more information when this happens? > > Right now, we don't even know if this is an erofs problem (and if this > ever was). It is just one of several candidates. I have no idea since I'm not working on PSI stuffs. But I guess you could record more frame addresses to get the caller of readahead_expand()? e.g. __builtin_return_address(1)? Also btw, is _RET_IP_ stable among all cases as readahead_expand()? Thanks, Gao Xiang > > Max