From patchwork Sun Dec 3 19:32:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yury Norov X-Patchwork-Id: 13477475 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 383C2C10DCE for ; Sun, 3 Dec 2023 19:33:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=tpP3nPf58Gp0taPNP29WVuAy8VudyFsYMAtV4wKHC+0=; b=rSZF8FguinytDN nWnFarjTFt9N8Ik+QkyyGQJsbd6sMci+AA6cULQlvaxjcSVAR9kzy/OkBBRtsnAgbTxNP1BzvUXLN rNIFCih/kT8QZx4TGQIM4x/VvaBgbjXQMT2wOnyuOCuNXCEkFm5P7vY1bfdLnyQAKvrxL+xaHWYeV P19BXHIxtB5Wa2EYWbZVx82cjgXuMSrj1FjENBB6YquLL4qFV4z3oILNUa07J2jBihKs1judgnNjh 7OvmWJOb2eZjzN2T5+j+4lbwt98A/2FdPN2e4e0A6HJGjvIATKy1+QBV/GesHwJ6Mtg7A+IhipE6N exYaf0zcJ9R+GqAaZKiA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r9sDZ-002W4N-0F; Sun, 03 Dec 2023 19:33:29 +0000 Received: from mail-yw1-x112a.google.com ([2607:f8b0:4864:20::112a]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r9sDV-002W2H-2E for linux-arm-kernel@lists.infradead.org; Sun, 03 Dec 2023 19:33:27 +0000 Received: by mail-yw1-x112a.google.com with SMTP id 00721157ae682-5d3efc071e2so27866817b3.0 for ; Sun, 03 Dec 2023 11:33:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701632005; x=1702236805; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Ngf7R2trkvhy5az0BJAYMgMmwp9GyrCv5kj64azD/XY=; b=b0Ayi0j2tOvjUlsLfSfGLzas90iXqc2OUx0pQ0nva8NHf2692fiVHtQE5yKizKcYxo x1czVZpZA6XQlTSe1n6t4H/kF1y+aR4XHstmvDBVwwPs1EQ5m2Kyx+haxfqPk5KIPCV/ KuMazxXrf3ruqLpv5ASHD8yYV+tcs2uWMhMmVvhr8RtkMiw5BHs9ygolTvnNs7a0op8Z anNbpEgr3XcVrh0MHcrERhownJr4SlN+yCYWcBuyj9cmQlL0H0BRp99X6uNjzTtRHT8b Ec4+bHqwJK09q2ZuWW8bZ/FynMimWficdGYWy4yqfGfKHTqwAYGp+n/pjvB8Jja6LptR +K5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701632005; x=1702236805; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ngf7R2trkvhy5az0BJAYMgMmwp9GyrCv5kj64azD/XY=; b=O3urjlYtHq06Tj9Rr3HjkugvXDPWyfAqAJx3Ecy57HyaXNWFnMM+nLzX0nC79EabF3 0+D01CmaJjbQqbh1wrwOS5jElZEgULJQEmzgzadYky4kR+whKdkkZRVgSzxUEK57la5U 3X6joVSRN54ktdcQPrRLvKhOplv26SfMWVRmOhY4s8RpBY9cypySOv6vBiH/8rKYow9Z OPCwz3/TE/BDnviE+3UQVCJIIojgd/yU4ggoubXIbCNNtwCt9F1vFoZ9ZfIsB58RQg5o 3LyGyizbwxXVhfgYHG7eaKEqYHz4MfUQlHxa29iJH2NyGtWYkgHljwLjXZd19Uy7v+Ie nfdA== X-Gm-Message-State: AOJu0Yzx2ih371kbcdQIqwT7j73h/FkFiv0OmRHyuQ4wvkDQMiWOFdxi WerwsL0daqsAH3P4mRmjm2U= X-Google-Smtp-Source: AGHT+IGAhPIRobNSBd8Xh5ROPApH6LYXWQ7wTkKlfC05Y42RMAU/7AhplYR/16C573v1Ku+fj2bMHA== X-Received: by 2002:a81:af4c:0:b0:5d7:1941:2c1e with SMTP id x12-20020a81af4c000000b005d719412c1emr2165207ywj.75.1701632003638; Sun, 03 Dec 2023 11:33:23 -0800 (PST) Received: from localhost ([2601:344:8301:57f0:cb98:c3e:57c:8191]) by smtp.gmail.com with ESMTPSA id z14-20020a814c0e000000b005d14e254367sm2752264ywa.80.2023.12.03.11.33.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 03 Dec 2023 11:33:22 -0800 (PST) From: Yury Norov To: linux-kernel@vger.kernel.org, Shuai Xue , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org Cc: Yury Norov , Jan Kara , Mirsad Todorovac , Matthew Wilcox , Rasmus Villemoes , Andy Shevchenko , Maxim Kuvyrkov , Alexey Klimov , Bart Van Assche , Sergey Shtylyov Subject: [PATCH v2 09/35] drivers/perf: optimize ali_drw_get_counter_idx() by using find_bit() Date: Sun, 3 Dec 2023 11:32:41 -0800 Message-Id: <20231203193307.542794-8-yury.norov@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231203193307.542794-1-yury.norov@gmail.com> References: <20231203192422.539300-1-yury.norov@gmail.com> <20231203193307.542794-1-yury.norov@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231203_113325_805284_FD18ADED X-CRM114-Status: GOOD ( 12.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The function searches used_mask for a set bit in a for-loop bit by bit. We can do it faster by using atomic find_and_set_bit(). Signed-off-by: Yury Norov Acked-by: Will Deacon --- drivers/perf/alibaba_uncore_drw_pmu.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c index 19d459a36be5..2a3b7701d568 100644 --- a/drivers/perf/alibaba_uncore_drw_pmu.c +++ b/drivers/perf/alibaba_uncore_drw_pmu.c @@ -274,15 +274,9 @@ static const struct attribute_group *ali_drw_pmu_attr_groups[] = { static int ali_drw_get_counter_idx(struct perf_event *event) { struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu); - int idx; + int idx = find_and_set_bit(drw_pmu->used_mask, ALI_DRW_PMU_COMMON_MAX_COUNTERS); - for (idx = 0; idx < ALI_DRW_PMU_COMMON_MAX_COUNTERS; ++idx) { - if (!test_and_set_bit(idx, drw_pmu->used_mask)) - return idx; - } - - /* The counters are all in use. */ - return -EBUSY; + return idx < ALI_DRW_PMU_COMMON_MAX_COUNTERS ? idx : -EBUSY; } static u64 ali_drw_pmu_read_counter(struct perf_event *event)