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=-0.8 required=3.0 tests=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 74E2BC433E0 for ; Sat, 16 May 2020 23:39:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4064D206D8 for ; Sat, 16 May 2020 23:39:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726876AbgEPXjc (ORCPT ); Sat, 16 May 2020 19:39:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726729AbgEPXjc (ORCPT ); Sat, 16 May 2020 19:39:32 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0042C061A0C; Sat, 16 May 2020 16:39:31 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 0E03E126390CD; Sat, 16 May 2020 16:39:30 -0700 (PDT) Date: Sat, 16 May 2020 16:39:27 -0700 (PDT) Message-Id: <20200516.163927.1112911965183377217.davem@davemloft.net> To: shakeelb@google.com Cc: edumazet@google.com, willemb@google.com, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net/packet: simply allocations in alloc_one_pg_vec_page From: David Miller In-Reply-To: References: <20200516021736.226222-1-shakeelb@google.com> <20200516.134018.1760282800329273820.davem@davemloft.net> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 16 May 2020 16:39:30 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shakeel Butt Date: Sat, 16 May 2020 15:35:46 -0700 > So, my argument is if non-zero order vzalloc has failed (allocations > internal to vzalloc, including virtual mapping allocation and page > table allocations, are order 0 and use GFP_KERNEL i.e. triggering > reclaim and oom-killer) then the next non-zero order page allocation > has very low chance of succeeding. Also not true. Page table allocation strategies and limits vary by architecture, they may even need virtual mappings themselves. So they can fail in situations where a non-zero GFP_KERNEL page allocator allocation would succeed.