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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 3DA04C169C4 for ; Tue, 29 Jan 2019 09:38:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0ADF1214DA for ; Tue, 29 Jan 2019 09:38:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EJjAgKPr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728068AbfA2JiF (ORCPT ); Tue, 29 Jan 2019 04:38:05 -0500 Received: from merlin.infradead.org ([205.233.59.134]:56312 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726923AbfA2JiE (ORCPT ); Tue, 29 Jan 2019 04:38:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=/56xF6oLfxBmXgnzr3HBj0IOJtYizlwY+A20yEDsDUE=; b=EJjAgKPrd72y8UvlmQ6giHTSb kYP0ZJOh+i7vazGZyb9ZhXP6U447rYRkfHudIdnsVlYzA/QNYjmZ9RTXTSwfzDceBadtsySCbmGfS KLkm1Hd49GPBOD9LrErMxm1cjdx1OMXX7wPTDD6xMMx2HkzQpqDEgUaaJkbN1QbN0PkkHyocQxw6E DYWRJXPk5Vl2gaAjyYrBDolJiBVqIMtAHeWE0aPbwlCW2E/6DlpDJZXYwitiCnYqfj5dHNNYD3VOe omJ45qpmd2z/b45SImOi14wqNgjvIXDgFVFlRUkhIlTxAACwB10Ck0nxzz9twCgeP6RjVnWprJEUf 37X6iCWwg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1goPq2-0008Lt-9F; Tue, 29 Jan 2019 09:37:50 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9FB842042CFA9; Tue, 29 Jan 2019 10:37:48 +0100 (CET) Date: Tue, 29 Jan 2019 10:37:48 +0100 From: Peter Zijlstra To: Elena Reshetova Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, keescook@chromium.org, tglx@linutronix.de Subject: Re: [PATCH 1/3] perf: convert perf_event_context.refcount to refcount_t Message-ID: <20190129093748.GF28467@hirez.programming.kicks-ass.net> References: <1548678448-24458-1-git-send-email-elena.reshetova@intel.com> <1548678448-24458-2-git-send-email-elena.reshetova@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1548678448-24458-2-git-send-email-elena.reshetova@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 28, 2019 at 02:27:26PM +0200, Elena Reshetova wrote: > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 3cd13a3..a1e87d2 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -1171,7 +1171,7 @@ static void perf_event_ctx_deactivate(struct perf_event_context *ctx) > > static void get_ctx(struct perf_event_context *ctx) > { > - WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); > + WARN_ON(!refcount_inc_not_zero(&ctx->refcount)); This could be refcount_inc(), remember how that already produces a WARN when we try and increment 0.