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 01181C4167B for ; Sun, 3 Dec 2023 19:33:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234062AbjLCTde (ORCPT ); Sun, 3 Dec 2023 14:33:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233996AbjLCTdX (ORCPT ); Sun, 3 Dec 2023 14:33:23 -0500 Received: from mail-yw1-x1132.google.com (mail-yw1-x1132.google.com [IPv6:2607:f8b0:4864:20::1132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A67111A for ; Sun, 3 Dec 2023 11:33:26 -0800 (PST) Received: by mail-yw1-x1132.google.com with SMTP id 00721157ae682-5c8c26cf056so42215287b3.1 for ; Sun, 03 Dec 2023 11:33:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701632005; x=1702236805; darn=vger.kernel.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=IwKOPKag07y4huwL4cYByFMZ4ox6UM2TxGUgmyL7qXkNd4B7hk/1v3OP3uTVD45TUl 6KRVs0b5ttTlv8O5W1j3phXev8jg+zHmAoJ0BopucQxDnAOxjcJFU5V49926lpD6MtZE 8vQET7xJBeOxn9bpPOA4PffBWwA9jV2s0gx0BBbRvwcn3+f95geuyT3QQtdfGDkJ0DN7 dw4WAy0A9a0uzFQjFGygqKOfnBPdf8vfREUnqO5Tjjk16Zf2zcJwcAYrTS1vU0qKKc1m QAkmnJgTVxG/eFZy6PW1SoXROBd+mQCRGwiBlZMVjLdxESyXXYkv4GeEeLLcbpqsGIhr RRCA== 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=KRdfzlhDkbdWLogLJJhRPaE8voIIyd88qjKSKJ1m29er7d/DTo5N7vzxn8fl+MoKOA tPWRJ4iNnJpPc7U0uRdGwlctisxh1fxy5CcKG94oPJWua7mXbZ57dYRDzELg2CkMhL7m oXzw6UcFB6v8WhUeQAoMtGlv3WjTJOUShawUrjrRR8bOuZZFSU6dEZ/4o0xbOcEHPD6V 9zCwVCPvt9RcuF1g33NMZIvCyocdBxDnbWNoS2MuVpg0zjoz6S2Ee1QP9oYU2ErF58tb oyt82QH3+y5c93zFQc1u+TVbkFlEpQV6uHxTbil2wCDgDvFIhc7iifZHCjAbwTCOkS4/ w0iQ== X-Gm-Message-State: AOJu0Yzs37z+mZG2/b2FDxN/eonWUiSUMEzWPtXi5VlwJClU5ico1r2o P148ucVkYobeLseSJvYgqBdEB2VbhjOSgg== 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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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) -- 2.40.1