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 C367DC07E9D for ; Mon, 26 Sep 2022 14:20:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2BB048E005B; Mon, 26 Sep 2022 10:20:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 26A338E0047; Mon, 26 Sep 2022 10:20:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 158D68E005B; Mon, 26 Sep 2022 10:20:18 -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 0AF248E0047 for ; Mon, 26 Sep 2022 10:20:18 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id B31A2A0CB9 for ; Mon, 26 Sep 2022 14:20:17 +0000 (UTC) X-FDA: 79954446474.27.67DFACA Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [193.142.43.52]) by imf19.hostedemail.com (Postfix) with ESMTP id 3B8A41A0018 for ; Mon, 26 Sep 2022 14:20:16 +0000 (UTC) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1ocoxx-0005nw-PT; Mon, 26 Sep 2022 16:20:13 +0200 Date: Mon, 26 Sep 2022 16:20:13 +0200 From: Florian Westphal To: Michal Hocko Cc: Florian Westphal , linux-mm@kvack.org, linux-kernel@vger.kernel.org, vbabka@suse.cz, akpm@linux-foundation.org, urezki@gmail.com, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, Martin Zaharinov Subject: Re: [PATCH mm] mm: fix BUG with kvzalloc+GFP_ATOMIC Message-ID: <20220926142013.GF12777@breakpoint.cc> References: <20220923133512.GE22541@breakpoint.cc> <20220926075639.GA908@breakpoint.cc> <20220926100800.GB12777@breakpoint.cc> <20220926130808.GD12777@breakpoint.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf19.hostedemail.com: domain of fw@strlen.de designates 193.142.43.52 as permitted sender) smtp.mailfrom=fw@strlen.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664202016; a=rsa-sha256; cv=none; b=HJqvNB8qe/OquLJBLYlPF9htoRfj2G/icT5OSszaLy4nUp8OcGzorXgjJUUZwsZG9Xb2aa HilofnR9KRRDvKKITfdSEVWMEE2M5Oap+wDSMUpEmX4uz0x2bTW4YwNCGd9BEV60rvvyHD i+J22WdZRfmLDBOvS+aoIa5WXjxjzNo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664202016; 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; bh=NeyoALofU7GpGegNrtdzct27tGQtoZg/2aXT+vQvuDg=; b=NCR1oUS1yVH3BTurXV2e6Hv8G9WupiIOz3cnO3Hs2V6Il3XmK4O+0QOpaPSwmL0HuWnRVA 1m67az3mj9kKVnwn4CKQRaTw3FVQ2CVoSxBazRmk0xc98ocOZ8w9rUT+OtXf3JLejMjbx8 8+Kq+YSho0iFijgL8hoQy5SxH2sUxZ4= X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 3B8A41A0018 X-Rspam-User: Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf19.hostedemail.com: domain of fw@strlen.de designates 193.142.43.52 as permitted sender) smtp.mailfrom=fw@strlen.de X-Stat-Signature: rf9amezxk34e9u86ziyeyn97irqw1hpn X-HE-Tag: 1664202016-109552 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: Michal Hocko wrote: > On Mon 26-09-22 15:08:08, Florian Westphal wrote: > [...] > > To the best of my knowledge there are users of this interface that > > invoke it with rcu read lock held, and since those always nest, the > > rcu_read_unlock() won't move us to GFP_KERNEL territory. > > Fiar point. I can see a comment above rhashtable_insert_fast which is > supposed to be used by drivers and explicitly documented to be > compatible with an atomic context. So the above is clearly a no-go > > In that case I would propose to go with the patch going > http://lkml.kernel.org/r/YzFplwSxwwsLpzzX@dhcp22.suse.cz direction. FWIW that patch works for me. Will you do a formal patch submission?