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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 82CF8C43457 for ; Mon, 19 Oct 2020 15:29:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 185162231B for ; Mon, 19 Oct 2020 15:29:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="yvag/1Wy"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="IQqz/onU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730064AbgJSP3N (ORCPT ); Mon, 19 Oct 2020 11:29:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729910AbgJSP3N (ORCPT ); Mon, 19 Oct 2020 11:29:13 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44C3BC0613CE; Mon, 19 Oct 2020 08:29:13 -0700 (PDT) Date: Mon, 19 Oct 2020 17:29:09 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603121351; h=from:from:reply-to:subject:subject: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=SSA1rgI9oUHNMXQCJ0EHFIg5+7llZCrIXvKF9z6SCbw=; b=yvag/1WyE7YGO01tuOZMVDXYJVVbRSZUTTDcNEFrW2Szp/K6KmRMXSdrwwJh0jiFmcGJLY 8KE6KOMD91iSqyY/CyDUCrqp/hAKY1ILkKnYqLfuhW8O5IW0a9jGHHDikT1fNnfmJ/Fgav 3C5W0+duxLTiCXtadB7bTetmmPu6616zmO3m0aie/2Hnh9nX8DmrYUIS/byQ9/x1a4ysRF oviWNZFtVpiXa0WdOMA1dSkH1t4fzBXGOsEbei86vRflWSjW7Pym78fr/8t/x/6jwgyXCu 4Kpxjs0IEaN7cXS0MkaOiv08H5Qi3dAv7EW75YhcfDSCCrTfSiPb8yccXJa4KQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603121351; h=from:from:reply-to:subject:subject: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=SSA1rgI9oUHNMXQCJ0EHFIg5+7llZCrIXvKF9z6SCbw=; b=IQqz/onU2+jf4eNXTVcyVbj2HSt8tXuWdeTBN+hX+PstwLXy8ahJIUMMkGX0/vlc3putCI MM5QglGrGXuSwfDw== From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: Minchan Kim , Mikhail Gavrilov , Linux List Kernel Mailing , linux-block@vger.kernel.org, Mike Galbraith , ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, Andrew Morton Subject: Re: [PATCH] zram: Fix __zram_bvec_{read,write}() locking order Message-ID: <20201019152909.rlnhqokqhhauq2kw@linutronix.de> References: <20201016124009.GQ2611@hirez.programming.kicks-ass.net> <20201016153324.GA1976566@google.com> <20201019101353.GJ2628@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201019101353.GJ2628@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-10-19 12:13:53 [+0200], Peter Zijlstra wrote: > > Mikhail reported a lockdep spat detailing how __zram_bvec_read() and > __zram_bvec_write() use zstrm->lock and zspage->lock in opposite order. > > Reported-by: Mikhail Gavrilov > Signed-off-by: Peter Zijlstra (Intel) > Tested-by: Mikhail Gavrilov We have the same patch in RT. I didn't submit it with the other local-lock patches because this splat pops up once pin_tag() is made a sleeping lock. I missed the part where migrate_read_lock() can be a lock. So: Acked-by: Sebastian Andrzej Siewior Sebastian