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=-3.6 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 54FC5C4361B for ; Sun, 20 Dec 2020 01:19:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7800422D3E for ; Sun, 20 Dec 2020 01:19:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7800422D3E 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 D58B46B005C; Sat, 19 Dec 2020 20:19:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CE2776B005D; Sat, 19 Dec 2020 20:19:06 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B82FC6B0068; Sat, 19 Dec 2020 20:19:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0200.hostedemail.com [216.40.44.200]) by kanga.kvack.org (Postfix) with ESMTP id 9A9866B005C for ; Sat, 19 Dec 2020 20:19:06 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 5E151180AD82F for ; Sun, 20 Dec 2020 01:19:06 +0000 (UTC) X-FDA: 77611901892.17.owl50_380c9112744a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 41FB8180D0180 for ; Sun, 20 Dec 2020 01:19:06 +0000 (UTC) X-HE-Tag: owl50_380c9112744a X-Filterd-Recvd-Size: 2261 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Sun, 20 Dec 2020 01:19:04 +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=nTty+Jb7NFfcXZE4+MmMpQCASKTBw2ev6K5BlwoCsxM=; b=tfnJmYiq7rvKVwzvOGc0xjJ7L7 glDSJWXNHGD8nBPb1x09mxZ6pJeoLDMIs3IMqjvczp136k4RrLHJYwgwKGsMOIDIXYR3Bg3MlTuFM HBj4MZeRtt6KDfjKo84f6m6M0hocmod82cjYGgA4H1it4HxjvhhPLp/qWrNuD+mLfreHozYTFQ3lu kJn4vaoaFcPgp393aaKOlVor+SyK55zEwqY4g6BkAGS90nv8tS3pheNvt8S9tZYF8dv0ffx0/sE3O dYa6jO/fdHkc0MsKOo+2GywcRRt8IrI02CbvyVGhnkrtnA6GYVyQ4+nvI8r27DXqPYcByCthM2M3z Hiz1op4g==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kqnMp-0001Wz-5k; Sun, 20 Dec 2020 01:18:35 +0000 Date: Sun, 20 Dec 2020 01:18:35 +0000 From: Matthew Wilcox To: Vitaly Wool Cc: Mike Galbraith , LKML , linux-mm , Barry Song , Sebastian Andrzej Siewior , Minchan Kim , NitinGupta Subject: Re: [PATCH] zsmalloc: do not use bit_spin_lock Message-ID: <20201220011835.GU15600@casper.infradead.org> References: <18669bd607ae9efbf4e00e36532c7aa167d0fa12.camel@gmx.de> <20201220002228.38697-1-vitaly.wool@konsulko.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201220002228.38697-1-vitaly.wool@konsulko.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000023, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Dec 20, 2020 at 02:22:28AM +0200, Vitaly Wool wrote: > zsmalloc takes bit spinlock in its _map() callback and releases it > only in unmap() which is unsafe and leads to zswap complaining > about scheduling in atomic context. > > To fix that and to improve RT properties of zsmalloc, remove that > bit spinlock completely and use a bit flag instead. Isn't this just "I open coded bit spinlock to make the lockdep warnings go away"?