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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 609B0C55178 for ; Thu, 5 Nov 2020 17:16:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 32B072083B for ; Thu, 5 Nov 2020 17:16:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="CjAEepDP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 32B072083B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7E5AA6B0150; Thu, 5 Nov 2020 12:16:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 796FF6B0151; Thu, 5 Nov 2020 12:16:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 685776B0152; Thu, 5 Nov 2020 12:16:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id 3B3336B0150 for ; Thu, 5 Nov 2020 12:16:10 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 9BC70362C for ; Thu, 5 Nov 2020 17:16:09 +0000 (UTC) X-FDA: 77451017658.22.deer76_3b0f804272cb Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id 6556718038E67 for ; Thu, 5 Nov 2020 17:16:09 +0000 (UTC) X-HE-Tag: deer76_3b0f804272cb X-Filterd-Recvd-Size: 2329 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Nov 2020 17:16:08 +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=TIMBZnXKHyOtxwMG5kXS9tUqJFNVBMccMaKyX1NX5R0=; b=CjAEepDPVQZLN6qOIzsJGM923K zZnZQe7kUZGTS2csOQBu+mu4iriCbf/emFFoRNft8e0FHo2mkpOTEVDbW8mSYIZ5oRwIkRyYVirIE sfbNMEhVgUlpuuKVyf4MVnAlEZsQ6ZteKpmo9Ttqwwbj2h2B3iLv+KVsMNAml8drpsxSRRpx38lqY C6J1uvn+vMPiaEjcpYfIeH3EerCb8tlqnBe9LiN94dryFEujdoV1hwiUuawkz1vnQai9gzZMokhAC /DTZU8cc17QgQFC1fiAxKUc7bh2BbO4ohZgIPgHpW/+PHeIjOLFxGZ2+UGMssKqefBt2xBY5MAU7i YHeDD0tA==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kairi-0008Mx-FS; Thu, 05 Nov 2020 17:16:02 +0000 Date: Thu, 5 Nov 2020 17:16:02 +0000 From: Matthew Wilcox To: Minchan Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm , "Aneesh Kumar K . V" , Harish Sriram , stable@vger.kernel.org Subject: Re: [PATCH] Revert "mm/vunmap: add cond_resched() in vunmap_pmd_range" Message-ID: <20201105171602.GP17076@casper.infradead.org> References: <20201105170249.387069-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201105170249.387069-1-minchan@kernel.org> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Nov 05, 2020 at 09:02:49AM -0800, Minchan Kim wrote: > This reverts commit e47110e90584a22e9980510b00d0dfad3a83354e. > > While I was doing zram testing, I found sometimes decompression failed > since the compression buffer was corrupted. With investigation, > I found below commit calls cond_resched unconditionally so it could > make a problem in atomic context if the task is reschedule. I don't think you're supposed to call unmap_kernel_range() from atomic context. At least vfree() punts to __vfree_deferred() if in_interrupt() is true. I forget the original reason for why that is.