From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754309AbbKBRYM (ORCPT ); Mon, 2 Nov 2015 12:24:12 -0500 Received: from smtprelay0192.hostedemail.com ([216.40.44.192]:48212 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752873AbbKBRYI (ORCPT ); Mon, 2 Nov 2015 12:24:08 -0500 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1538:1593:1594:1711:1714:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3351:3622:3865:3866:3867:3868:3870:3871:3872:5007:6119:6261:7875:7903:10004:10400:10848:10967:11232:11658:11914:12296:12517:12519:12740:13069:13180:13229:13311:13357:21060:21080:30054:30070:30090:30091,0,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,LFtime:3,LUA_SUMMARY:none X-HE-Tag: peace45_6bbf75fa2e0f X-Filterd-Recvd-Size: 1734 Date: Mon, 2 Nov 2015 12:24:05 -0500 From: Steven Rostedt To: "Shi, Yang" Cc: Daniel Borkmann , Alexei Starovoitov , ast@kernel.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, netdev@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: Re: [PATCH] bpf: convert hashtab lock to raw lock Message-ID: <20151102122405.56dd97a1@gandalf.local.home> In-Reply-To: <5637997D.1020502@linaro.org> References: <1446243386-26582-1-git-send-email-yang.shi@linaro.org> <20151031000356.GA28070@Alexeis-MacBook-Pro.local> <20151031094736.494427d7@grimm.local.home> <56350A86.5090500@iogearbox.net> <5637997D.1020502@linaro.org> X-Mailer: Claws Mail 3.12.0 (GTK+ 2.24.28; 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, 02 Nov 2015 09:12:29 -0800 "Shi, Yang" wrote: > Yes, it is common practice for converting sleepable spin lock to raw > spin lock in -rt to avoid scheduling in atomic context bug. Note, in a lot of cases we don't just convert spin_locks to raw because of atomic context. There's times we need to change the design where the lock is not taken in atomic context (switching preempt_disable() to a local_lock() for example). But bpf is much like ftrace and kprobes where they can be taken almost anywhere, and the do indeed need to be raw. -- Steve