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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 AF858C43387 for ; Thu, 20 Dec 2018 18:38:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81D6720811 for ; Thu, 20 Dec 2018 18:38:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=synopsys.com header.i=@synopsys.com header.b="IgFvZuYi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389451AbeLTSif (ORCPT ); Thu, 20 Dec 2018 13:38:35 -0500 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:45386 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731506AbeLTSi1 (ORCPT ); Thu, 20 Dec 2018 13:38:27 -0500 Received: from mailhost.synopsys.com (mailhost2.synopsys.com [10.13.184.66]) by smtprelay.synopsys.com (Postfix) with ESMTP id CD80924E0772; Thu, 20 Dec 2018 10:38:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1545331107; bh=ZniTcl6EZWBBaGdAu2K3uR86MPgYLB4cmv9UcgqcvjU=; h=From:To:CC:Subject:Date:References:From; b=IgFvZuYiE+AJZnv1Qoht5p4oYVh3balSM8GlTQCXZBOpjdDkVSQoaqRhZm/0yBaqJ bNQUMWtbQ9fVFZM2P7Iy0MyJe3zMrEmSjJneSXs0zLA5vLtnQS11nbfSqPeN7guLqN XhgL4jqQLQw9iOur1a4K3MwVEPULixdjcyZmQwgGD4Ep3RhixxwVCnGwvnb6B5VB+F qYmlP5juXYkSTHvzgvUtWr4PgnrFfdgdtDkGJpuPECY70D1tL0MZ381o2RTAdQceKb gLh2vmkqeGIwjAlLsztgoycLA9vU+L41/inVjqnISBqR2QeP9trMtx0A95WEDkQIyc DSB5E2iDebIwQ== Received: from US01WXQAHTC1.internal.synopsys.com (us01wxqahtc1.internal.synopsys.com [10.12.238.230]) by mailhost.synopsys.com (Postfix) with ESMTP id C2F4D3A12; Thu, 20 Dec 2018 10:38:26 -0800 (PST) Received: from US01WEMBX2.internal.synopsys.com ([fe80::e4b6:5520:9c0d:250b]) by US01WXQAHTC1.internal.synopsys.com ([::1]) with mapi id 14.03.0415.000; Thu, 20 Dec 2018 10:38:26 -0800 From: Vineet Gupta To: Michal Hocko CC: "linux-snps-arc@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , Peter Zijlstra Subject: Re: [PATCH 1/2] ARC: show_regs: avoid page allocator Thread-Topic: [PATCH 1/2] ARC: show_regs: avoid page allocator Thread-Index: AQHUlwMR8PfsxZ55lUuwqgC40oqmmA== Date: Thu, 20 Dec 2018 18:38:26 +0000 Message-ID: References: <1545159239-30628-1-git-send-email-vgupta@synopsys.com> <1545159239-30628-2-git-send-email-vgupta@synopsys.com> <20181220125730.GA17350@dhcp22.suse.cz> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.144.199.106] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/20/18 4:57 AM, Michal Hocko wrote:=0A= >> Despite this, lockdep still barfs (see next change), but this patch=0A= >> still has merit as in we use smaller/localized buffers now and there's= =0A= >> less instructoh trace to sift thru when debugging pesky issues.=0A= > But show_regs is called from contexts which might be called from deep=0A= > call chains (e.g WARN). Is it safe to allocate such a large stack there?= =0A= =0A= ARC has 8K pages and 256 additional bytes of stack usage doesn't seem absur= dly=0A= high to me !=0A= =0A= -Vineet=0A=