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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 6F474CA9EA0 for ; Tue, 22 Oct 2019 09:25:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3ECC62084B for ; Tue, 22 Oct 2019 09:25:29 +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="sPEnRcrt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731473AbfJVJZ2 (ORCPT ); Tue, 22 Oct 2019 05:25:28 -0400 Received: from merlin.infradead.org ([205.233.59.134]:37278 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731338AbfJVJZX (ORCPT ); Tue, 22 Oct 2019 05:25:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=WY6KImieCGZAjEO6KzSr9f0KT5JTeFka9FBaH89KLj0=; b=sPEnRcrtXhmnfZeDpfkVk+nbEO D/Ik8q1Xi20bN9wIK5hZhQtXd9FC4yfqId+7etImPpvCCDInzVY6hO4/tUPb0/NkbcNwkgoKq15jV W6pw0BORHWaT/rn+XY/6u53jpB/BJTcvchHLNCkevdszLRnZ6hDE9j2Y7YsNMYrePx+GewF8bONM2 QYxm2jx6Tstxu7+d+x9vjAJ/oVDy9dDTHcps/CEWFiC7A+XDiXa4JavCeGPAuPDtaapGfvOM1LtP3 Xr/1QxKVyyyzRnhC6c1hHvKAa1lbvRI1AVQn7TNYvRREuoXScbkPyKzrpW3AgpffsZg3VtCkZvScZ wRJ4zExg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iMqPg-00029C-J9; Tue, 22 Oct 2019 09:25:12 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 93366301124; Tue, 22 Oct 2019 11:24:11 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 1F69420D8D3C2; Tue, 22 Oct 2019 11:25:09 +0200 (CEST) Message-Id: <20191022092307.483110884@infradead.org> User-Agent: quilt/0.65 Date: Tue, 22 Oct 2019 11:20:20 +0200 From: Peter Zijlstra To: mingo@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org Cc: acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, andi@firstfloor.org, kan.liang@linux.intel.com Subject: [PATCH 3/3] perf: Optimize perf_init_event() for TYPE_SOFTWARE References: <20191022092017.740591163@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Liang, Kan" Andi reported that he was hitting the linear search in perf_init_event() a lot. Now that all !TYPE_SOFTWARE events should hit the IDR, make sure the TYPE_SOFTWARE events are at the head of the list such that we'll quickly find the right PMU (provided a valid event was given). Reported-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10167,7 +10167,16 @@ int perf_pmu_register(struct pmu *pmu, c if (!pmu->event_idx) pmu->event_idx = perf_event_idx_default; - list_add_rcu(&pmu->entry, &pmus); + /* + * Ensure the TYPE_SOFTWARE PMUs are at the head of the list, + * since these cannot be in the IDR. This way the linear search + * is fast, provided a valid software event is provided. + */ + if (type == PERF_TYPE_SOFTWARE || !name) + list_add_rcu(&pmu->entry, &pmus); + else + list_add_tail_rcu(&pmu->entry, &pmus); + atomic_set(&pmu->exclusive_cnt, 0); ret = 0; unlock: