From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754628AbbCBTd0 (ORCPT ); Mon, 2 Mar 2015 14:33:26 -0500 Received: from smtprelay0024.hostedemail.com ([216.40.44.24]:56335 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753870AbbCBTdZ (ORCPT ); Mon, 2 Mar 2015 14:33:25 -0500 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1431:1437:1515:1516:1518:1534:1539:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3352:3622:3865:3866:3867:3868:3870:3871:3872:3874:4250:5007:6261:6691:7875:10004:10400:10848:10967:11232:11658:11914:12517:12519:12740:13069:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: kite92_7477bba28fc0f X-Filterd-Recvd-Size: 1700 Date: Mon, 2 Mar 2015 14:33:19 -0500 From: Steven Rostedt To: Alexei Starovoitov Cc: Tom Zanussi , Masami Hiramatsu , Namhyung Kim , Andi Kleen , LKML Subject: Re: [PATCH 07/15] mm: Add ___GFP_NOTRACE Message-ID: <20150302143319.4ae86674@gandalf.local.home> In-Reply-To: References: X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2 Mar 2015 11:24:04 -0800 Alexei Starovoitov wrote: > well, percentage of tracepoints called from NMI is tiny > comparing to the rest, so assuming nmi context > everywhere is very inefficient. > Like we can use pre-allocated pool of map entries when > tracepoint is called from NMI, but we shouldn't be using > it in other cases. Just like ring buffers and other things > have nmi and non-nmi pools and code paths, it doesn't > make sense to disallow kmalloc all together. > btw, calling kmalloc is _faster_ than taking > objects from cache-cold special nmi only pool. Please show the numbers and post the tests when stating something like that. -- Steve