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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF182C43334 for ; Mon, 4 Jul 2022 14:39:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232519AbiGDOjq (ORCPT ); Mon, 4 Jul 2022 10:39:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234851AbiGDOjO (ORCPT ); Mon, 4 Jul 2022 10:39:14 -0400 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76F0FEE14 for ; Mon, 4 Jul 2022 07:39:06 -0700 (PDT) Received: by mail-pf1-x42e.google.com with SMTP id g7so4349052pfb.10 for ; Mon, 04 Jul 2022 07:39:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=uNqvcKgo1+oe7KfjMD3BFid/MOvuDJRgw+z7dh4MpHg=; b=Rd5z8PJTAKeEtJxaGAFVCmXX2MztOoimi+HPammxoFcq0O6PnXW8JfFMtMvJp6haX4 N0zM5V0tjiNuFmpytb88WSTWOEnwywt0C6qP1EwTsCDXaX2dInDbnhxIPMzTowViP1bP 2ZZ8/AF9jglxfgKev3K+HAyB5vDOTavQMonRtdUVliPhnplSEZp0J+Phxb256DXUP32N E8SeZl8emqoBykXys17iDBDX+yrMLpLX/i11Cw85FEGSHDf827M85rRFl6o1PwCBvFQI 9B2n8L/5a6tMWzeIMGJL0m/ktzJI4GTnown2/j8btygQDhMAxvhMCNWQyAWIb5NajTOL xu8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=uNqvcKgo1+oe7KfjMD3BFid/MOvuDJRgw+z7dh4MpHg=; b=isu1nOLYGfYFzFcXhJFwd2JtDsqIHBT/fUZ0qJdE4ZKfGSzhECBmFOxz0LJLXLPlyl TKxVNVNzeaQf+3/NjllU3mVHYaoPvoV8xTXTWH9n3SUm2Uydyqp0k+QP2z8bdwIRIN24 ctTqCHWotBzv7kZRxXdBgXArEBnUrbHUvD4GHU2lLPjAPZnFpVizdn7oDRU3ItVjULQg LzAL7SyhKpSKny75WMIzz+RIHMc+e8bgFXPiYOrG3p4lEz+9U+njT2++ERgEjamaDyBr jw5ueOxd46hnQHn2YgkBcvlXd5kvRY4BnUjZk8tJ3sD5Kx4R0X3dV/DUU3+dDe0H0hmD APoQ== X-Gm-Message-State: AJIora/HAYSdTl8i5xPvbXpXVA+Y82kj6DG2dArzxsh4r4iCJS1lvLCw PU2uamfWMrx4U0WHlLPOLBE= X-Google-Smtp-Source: AGRyM1tcLyesZ4LqtcBwRRAPb3M8h4Y5icA5Z0GODpjLR7sKbKnD1cHPy3oh6p6Bf2qsw7Zg6nFYVA== X-Received: by 2002:a63:6c42:0:b0:3fe:465:7a71 with SMTP id h63-20020a636c42000000b003fe04657a71mr25203899pgc.101.1656945545785; Mon, 04 Jul 2022 07:39:05 -0700 (PDT) Received: from bobo.ozlabs.ibm.com ([203.221.247.188]) by smtp.gmail.com with ESMTPSA id u13-20020a63454d000000b0040d2224ae04sm20534365pgk.76.2022.07.04.07.39.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Jul 2022 07:39:05 -0700 (PDT) From: Nicholas Piggin To: Peter Zijlstra Cc: Nicholas Piggin , Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , linux-kernel@vger.kernel.org Subject: [PATCH 10/13] locking/qspinlock: paravirt use simple trylock in case idx overflows Date: Tue, 5 Jul 2022 00:38:17 +1000 Message-Id: <20220704143820.3071004-11-npiggin@gmail.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220704143820.3071004-1-npiggin@gmail.com> References: <20220704143820.3071004-1-npiggin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The mcs node overflow fallback locking case does not have to use pv_hybrid_queued_unfair_trylock as the trylock, which reduces the differences between pv and !pv cases. This was likely an artifact of function renaming making it use the pv trylock, which is not a bug but it is unexpected. Signed-off-by: Nicholas Piggin --- kernel/locking/qspinlock.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index 1d5b3443772c..cef0ca7d94e1 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -798,13 +798,8 @@ static inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, bool parav */ if (unlikely(idx >= MAX_NODES)) { lockevent_inc(lock_no_node); - if (paravirt) { - while (!pv_hybrid_queued_unfair_trylock(lock)) - cpu_relax(); - } else { - while (!queued_spin_trylock(lock)) - cpu_relax(); - } + while (!queued_spin_trylock(lock)) + cpu_relax(); goto release; } -- 2.35.1