From nobody Mon Feb 9 01:58:25 2026 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 0EE87C4332F for ; Tue, 12 Dec 2023 02:28:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345759AbjLLC2Z (ORCPT ); Mon, 11 Dec 2023 21:28:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345712AbjLLC2C (ORCPT ); Mon, 11 Dec 2023 21:28:02 -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 32BC9D5 for ; Mon, 11 Dec 2023 18:28:09 -0800 (PST) Received: by mail-yw1-x1132.google.com with SMTP id 00721157ae682-5e1a3199f6bso6896777b3.0 for ; Mon, 11 Dec 2023 18:28:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702348087; x=1702952887; 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=wOtgtWtIwGwJ1G9iBa8c13QOAAJ/9MITwOIhxFkc4ng=; b=PPYYK6gZjHpPN8gqQDwq9laUoxLJR5BRssNuC2urGmIwyElRbozZHvRUtt7/86JBhD xh1ZhXO/RKkAe2UzeroXBrd7WDIfnsKn1Nls2ux1an1mb0WJy3B002kFekxqyJb9MS/E Pk4bdzOU9/39GVQADWfzVii6riDnuYgOA5A5PTAalneKSG6dWSqPYMMNPMAlLPaE55hP g0BMXbfZ3cDz8fXBQ53z7qPeeiBvwJtIWCmlQA+Zt1EOXJF+MIxASO9BJdHL581CEmdv eNhj9IueQdDR+yAZhFcnsz0HwgJyur8mw7jLiseLClTgLAzdMhLyfqTVYlVDkxy5yWsn Yp4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702348087; x=1702952887; 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=wOtgtWtIwGwJ1G9iBa8c13QOAAJ/9MITwOIhxFkc4ng=; b=wCOgN6buPNynnODnf6ARhk9O4ZQMBqxyMhfGXMLq6+gUEYuudkz3NKlolhvSmdVeF5 MfeeGC0MeIqL4HtU27m47wtCOVOvI4W/QyReOIIRhFUkzTphNqLCWJ6oFf+FnDcM9hvR EWaOA9up6Ggm+xEP5wC0yQdPadqRLzRcVLSZzEfIizLn5sr6DOW6GINBuKDj/jE+1gd5 k+mWelQzoxpCKO40cQHAJufxwHXTxXnZGrN3h8vn8NZOvQPWLDfS0vFeDgJM9upzR0QL mdh+r7xEHnqh09RjNMa4Ww/8ppyGxmk1oc0l4mvoCWEsLtemFrRBCzcpQM8FMmTp8lfB zEBw== X-Gm-Message-State: AOJu0Yyw8P6yV2uVl0wm05UoXZcAR7uPDdtwVRsnF2t59fHo7i84wlYI u19vyEcKZWlJ/rv2jpEL+mvHpByDzRx1aw== X-Google-Smtp-Source: AGHT+IG3JcQqqXUlvmV9E4Jq3lvTw/W0aG3auxyNSagyZtjyoh921YIZwuIwFilGsSDgtbh9RCNWpQ== X-Received: by 2002:a81:7c89:0:b0:5d7:1941:2c2f with SMTP id x131-20020a817c89000000b005d719412c2fmr4754793ywc.92.1702348087359; Mon, 11 Dec 2023 18:28:07 -0800 (PST) Received: from localhost ([2601:344:8301:57f0:38aa:1c88:df05:9b73]) by smtp.gmail.com with ESMTPSA id a200-20020a0dd8d1000000b005d35a952324sm3449101ywe.56.2023.12.11.18.28.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Dec 2023 18:28:07 -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 v3 09/35] drivers/perf: optimize ali_drw_get_counter_idx() by using find_and_set_bit() Date: Mon, 11 Dec 2023 18:27:23 -0800 Message-Id: <20231212022749.625238-10-yury.norov@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231212022749.625238-1-yury.norov@gmail.com> References: <20231212022749.625238-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The function searches used_mask for a set bit in a for-loop bit by bit. Simplify it 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_u= ncore_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[] =3D { static int ali_drw_get_counter_idx(struct perf_event *event) { struct ali_drw_pmu *drw_pmu =3D to_ali_drw_pmu(event->pmu); - int idx; + int idx =3D find_and_set_bit(drw_pmu->used_mask, ALI_DRW_PMU_COMMON_MAX_C= OUNTERS); =20 - for (idx =3D 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; } =20 static u64 ali_drw_pmu_read_counter(struct perf_event *event) --=20 2.40.1