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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5F02C4332F for ; Mon, 17 Oct 2022 15:55:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1DD1F6B0074; Mon, 17 Oct 2022 11:55:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 18D926B0075; Mon, 17 Oct 2022 11:55:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 07DFA6B0078; Mon, 17 Oct 2022 11:55:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id E9CDC6B0074 for ; Mon, 17 Oct 2022 11:55:57 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id C4F8A1A0283 for ; Mon, 17 Oct 2022 15:55:57 +0000 (UTC) X-FDA: 80030892354.22.1DE835E Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf23.hostedemail.com (Postfix) with ESMTP id CD13914003B for ; Mon, 17 Oct 2022 15:55:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2vk4i5KDs+xhL9RL/prStipv82/5xCos0ckR6/mPo+o=; b=mkPEvM7rzQdNNDo31xw8Y6OxZk lpFKq0VgEJENhd+31JfDc8e2WKl8zTZ/9oWiNn9kEBgwXN4uifVfUKHdE77ELhL7ySFemwUJFADPM LKtYoPfakztqEu3KcdbxEN12BF3OGuWeLGD8qOIRO0dmaf0+OekQEAj66+RVavqFk7b8tsxMd9f8G FiCTjhnyGj/yBnNbvfpNl9V0cUFG4JOxti4ZRVI8se9YEWwnKjAiMTWDwZXmbCQEIZTXdniBwOOH8 gP7jDTHXq9XqJN4y1sQzb+h/zBnTeX76gFxdTVVNRun1hyX4xliuo6GZd0qs49k0GXhR4zl5th4Lz 4FoseLjw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1okSSz-009xFa-M3; Mon, 17 Oct 2022 15:55:49 +0000 Date: Mon, 17 Oct 2022 16:55:49 +0100 From: Matthew Wilcox To: Zhaoyang Huang Cc: "zhaoyang.huang" , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, ke.wang@unisoc.com, steve.kang@unisoc.com, baocong.liu@unisoc.com, linux-fsdevel@vger.kernel.org Subject: Re: [RFC PATCH] mm: move xa forward when run across zombie page Message-ID: References: <1665725448-31439-1-git-send-email-zhaoyang.huang@unisoc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666022156; a=rsa-sha256; cv=none; b=UetlX9ELUPqyqLpxdh+bdEIeFRq1wmet4kNeuRAMyf98P7VpFIAkqSGXMV9I7i6rfdAZFT LoizH7SzAuuF9cZRL+TcPIZIsjJii6MyWivbcNUpn/lQwIHEP2gdFYlSi9s+Kd17rsXurG VNhdLz4clXcOQjNDlUjjyacJjRpmIx0= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=mkPEvM7r; dmarc=none; spf=none (imf23.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666022156; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=2vk4i5KDs+xhL9RL/prStipv82/5xCos0ckR6/mPo+o=; b=3Ubn6rJuGRaJq0Mx5swuGWw4cWy5BENIm0k2m68WK6/NOr+xmOg0FCWcd4hzlqs28XIXfv ljTR4oW242VeYB4K6dpk7CgS0BXohmxhPvAJZGuDgKCLUYsxs9PSYVpa1gokcsLf/pHUNx 8mAKtz0ieVAbR2Z/M6Jkb+0gtj+XIuI= X-Rspamd-Server: rspam05 X-Rspam-User: X-Rspamd-Queue-Id: CD13914003B Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=mkPEvM7r; dmarc=none; spf=none (imf23.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: 5jpyatke4yqfq8eo7o5rqtm8eo3f564m X-HE-Tag: 1666022155-434326 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: On Mon, Oct 17, 2022 at 01:34:13PM +0800, Zhaoyang Huang wrote: > On Fri, Oct 14, 2022 at 8:12 PM Matthew Wilcox wrote: > > > > On Fri, Oct 14, 2022 at 01:30:48PM +0800, zhaoyang.huang wrote: > > > From: Zhaoyang Huang > > > > > > Bellowing RCU stall is reported where kswapd traps in a live lock when shrink > > > superblock's inode list. The direct reason is zombie page keeps staying on the > > > xarray's slot and make the check and retry loop permanently. The root cause is unknown yet > > > and supposed could be an xa update without synchronize_rcu etc. I would like to > > > suggest skip this page to break the live lock as a workaround. > > > > No, the underlying bug should be fixed. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > OK, could I move the xas like below? > > + if (!folio_try_get_rcu(folio)) { > + xas_next_offset(xas); > goto reset; > + }