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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 A4158C4360F for ; Tue, 2 Apr 2019 20:04:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E11E206B7 for ; Tue, 2 Apr 2019 20:04:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726409AbfDBUEX (ORCPT ); Tue, 2 Apr 2019 16:04:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39804 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725857AbfDBUEV (ORCPT ); Tue, 2 Apr 2019 16:04:21 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 665A33082A51; Tue, 2 Apr 2019 20:04:21 +0000 (UTC) Received: from localhost.default (ovpn-116-31.phx2.redhat.com [10.3.116.31]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AE0A6014A; Tue, 2 Apr 2019 20:04:18 +0000 (UTC) From: Daniel Bristot de Oliveira To: linux-kernel@vger.kernel.org Cc: Steven Rostedt , Arnaldo Carvalho de Melo , Ingo Molnar , Andy Lutomirski , Thomas Gleixner , Borislav Petkov , Peter Zijlstra , "H. Peter Anvin" , "Joel Fernandes (Google)" , Jiri Olsa , Namhyung Kim , Alexander Shishkin , Tommaso Cucinotta , Romulo Silva de Oliveira , Clark Williams , x86@kernel.org Subject: [RFC PATCH 3/7] trace: Optimize trace_get_context_bit() Date: Tue, 2 Apr 2019 22:03:55 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Tue, 02 Apr 2019 20:04:21 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org trace_get_context_bit() and trace_recursive_lock() uses the same logic, but the second reads the per_cpu variable only once. Uses the trace_recursive_lock()'s logic in trace_get_context_bit(). Signed-off-by: Daniel Bristot de Oliveira Cc: Steven Rostedt Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Andy Lutomirski Cc: Thomas Gleixner Cc: Borislav Petkov Cc: Peter Zijlstra Cc: "H. Peter Anvin" Cc: "Joel Fernandes (Google)" Cc: Jiri Olsa Cc: Namhyung Kim Cc: Alexander Shishkin Cc: Tommaso Cucinotta Cc: Romulo Silva de Oliveira Cc: Clark Williams Cc: linux-kernel@vger.kernel.org Cc: x86@kernel.org --- kernel/trace/trace.h | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index dad2f0cd7208..09318748fab8 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -635,20 +635,13 @@ enum { static __always_inline int trace_get_context_bit(void) { - int bit; - - if (in_interrupt()) { - if (in_nmi()) - bit = TRACE_CTX_NMI; + unsigned long pc = preempt_count(); - else if (in_irq()) - bit = TRACE_CTX_IRQ; - else - bit = TRACE_CTX_SOFTIRQ; - } else - bit = TRACE_CTX_NORMAL; - - return bit; + if (pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)) + return pc & NMI_MASK ? TRACE_CTX_NMI : + pc & HARDIRQ_MASK ? TRACE_CTX_IRQ : TRACE_CTX_SOFTIRQ; + else + return TRACE_CTX_NORMAL; } static __always_inline int trace_test_and_set_recursion(int start, int max) -- 2.20.1