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 643B1CDB465 for ; Mon, 16 Oct 2023 17:56:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E14D58002A; Mon, 16 Oct 2023 13:56:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D9DFA80029; Mon, 16 Oct 2023 13:56:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C3D5D8002A; Mon, 16 Oct 2023 13:56:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id A67CF80029 for ; Mon, 16 Oct 2023 13:56:20 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 255A8A0AAE for ; Mon, 16 Oct 2023 17:56:20 +0000 (UTC) X-FDA: 81352078920.13.E3B76EB Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf06.hostedemail.com (Postfix) with ESMTP id E725F180009 for ; Mon, 16 Oct 2023 17:56:17 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=dGuZgk5g; dmarc=none; spf=none (imf06.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=1697478978; 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=/SdjzNKC8llTqbzK5M4yd54rZVBEOFB52/z6QfMDo7U=; b=PJzT/wPl1yTLQupLJCgGhafPFkfKxmcex58zeuX1a5F9tW07N/JlHZq7aDAtJOH3dh1dVW 6fIFA1TqH6zrfXU995Nc9BgKdPVoI2eWOsypy3jv8Wuw79UE1QRmQXPRbIUKqeZpYZBrCb glPrbwAv4W3EpFf1jmFXQYo99CoW1oA= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=dGuZgk5g; dmarc=none; spf=none (imf06.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1697478978; a=rsa-sha256; cv=none; b=ZewOd1IbDGaGwuRnJ6za5LS5x0Jx3bcCvFb0V6Dj4dn2pg8HY0bvUUWl32VAvU7MpJXkL5 dU2mtvmxtN8g3dbuZrFGWNX2DRw4tppHfvVmH44hkUy/N9LuLU2eENVLBLNbz6TO0ItGwA mXegV6J9cgkUuYTsQbwkGqeIsTgFOhA= 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=/SdjzNKC8llTqbzK5M4yd54rZVBEOFB52/z6QfMDo7U=; b=dGuZgk5gVAdiUWyjNrLk9vr6D2 Hb5y6FVBXRUfRBvHyn+Soa4vyCFm/FodV4eLxDheai2PTmCSQLd394tBXQz3m3kgacb7+kZMAp602 gx4EvxUI56Rz7+typFCFgG0VRpIkDZppCfjGyv92LJEtGp98KsFiy0uJJ/UsyLdZ8G3TsI2pyHFLL ZE4z2j4IBfvuKiBdGwHl74ZG2Rbj9EUQpTBtepWwbMaUJDZWqlPZzdh3VNQJWPMJyKCw3rI9CIuJ9 Z6fosUBoYWdv7tNwO8hJJgwpPz/lx0wBPm0pi51uiwTnKESpsIH9AsDCiYnJes74nG3hVG3NLK0Lv kFQ3+GPA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qsRob-007TKi-E0; Mon, 16 Oct 2023 17:55:41 +0000 Date: Mon, 16 Oct 2023 18:55:41 +0100 From: Matthew Wilcox To: "Kirill A. Shutemov" Cc: Borislav Petkov , Andy Lutomirski , Dave Hansen , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel , Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Dario Faggioli , Mike Rapoport , David Hildenbrand , Mel Gorman , marcelo.cerri@canonical.com, tim.gardner@canonical.com, philip.cox@canonical.com, aarcange@redhat.com, peterx@redhat.com, x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org, Nikolay Borisov Subject: Re: [PATCHv2] efi/unaccepted: Fix soft lockups caused by parallel memory acceptance Message-ID: References: <20231016163122.12855-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231016163122.12855-1-kirill.shutemov@linux.intel.com> X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: E725F180009 X-Stat-Signature: 5twip4iwqmfyfdo5b5j5oszomynrid5n X-HE-Tag: 1697478977-737149 X-HE-Meta: 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 vmVKWou5 ughpP0G7Cz2pf/84vNS373PANtBZxMZVkPihtmTtxRdp9UJJQnuNYQbaje6Am2oMPCre2OUeW8GTSEFrDvZZDgMQOEto08hCqNrpn9UdZwyErso6otS1oVotG3JysHQiXWXQGzC6ezcyYDU4= 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 16, 2023 at 07:31:22PM +0300, Kirill A. Shutemov wrote: > v2: > - Fix deadlock (Vlastimil); > - Fix comments (Vlastimil); > - s/cond_resched()/cpu_relax()/ -- cond_resched() cannot be called > from atomic context; Isn't there an implicit cpu_relax() while we're spinning? Does this really accomplish anything? > +retry: > spin_lock_irqsave(&unaccepted_memory_lock, flags); [...] > + spin_unlock_irqrestore(&unaccepted_memory_lock, flags); > + > + /* > + * The code is reachable from atomic context. > + * cond_resched() cannot be used. > + */ > + cpu_relax(); > + > + goto retry;