From nobody Tue Dec 16 13:22:49 2025 Received: from mail-pg1-f170.google.com (mail-pg1-f170.google.com [209.85.215.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1DDEA1BD915 for ; Thu, 20 Jun 2024 17:57:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.170 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718906256; cv=none; b=RkxlpJ87bwgSFaOciqKoOfdrNpkBuyzH2pUYpKJVhgw7bNfE/6NJzePkaeg9CTL+oa5HG95cKbW/27wvsYdivv+rUZAcAV7aUzNY3rWRCBBd48GMbkxkxHvRlTy1VybbuaCDTsGdDHTs88jCig7uQIBOYjoKIfuSE9MC7hx5Y1s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718906256; c=relaxed/simple; bh=IJH0Xr1pzPS2QRONxWqkkm6N53c8msn9QYo80VGvKXU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OKysLKrFIzbQFUfc/QCLTDD8cCI/x2XpSYciPc5rCax+PTGxdktdLDl0Zk11eVu78/cKaQunNJ/kfSY7eSHDLbsB3k1N3u6SECR7Drf3usNRuTw5a13sbdISJwnIi+vMTYx8+rvhXbIsvA4pUOlrup9cTuzlDKM/C0QJwb3/iWw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=MUwu9T40; arc=none smtp.client-ip=209.85.215.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MUwu9T40" Received: by mail-pg1-f170.google.com with SMTP id 41be03b00d2f7-6e41550ae5bso903926a12.3 for ; Thu, 20 Jun 2024 10:57:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1718906254; x=1719511054; 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=V5DGzLYbAUAdrqbJyW80kv/C/QU59EDA9QcwDgDhhzU=; b=MUwu9T40imIjXvxFeNDOMqpFLMD7DqnrIFwdIO87dT2BGC0rNjG9nrBKp3E0WHBULS IlYlVkxGELvGw+5SWCxK0+7e5a3XCCKtjD26h6O6hXmZR8UyHCKSXLx/MLud50ow6idi e5XAE7uGc8SsU3UFDrmDs7Rt2ftWVSSkTG+pco22wBCx5fPejDWtrPuNzwM/vAB6HW/2 INnx5MfIGOzZ0fYNMIk8Gw9vfJpD4cs6Y91LvjSXFmnDWmaZ9ppyKxQvoicQTYLkfI1n nL/ao5PkQFpYbUgf5STpVC8q/fjuP5ZZsgmeM34Kwm20cVlRzBgQDEATjx03/t5pnLBl upPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718906254; x=1719511054; 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=V5DGzLYbAUAdrqbJyW80kv/C/QU59EDA9QcwDgDhhzU=; b=er3zW+n4JW8/FZzZVTshc2IfXeSFdSTZFURJt3U9u+U+1Cr9IrcK7Tr3CAHf80pzPm DXrarcTbK4JdhHlWbk+M1zLqqTDz6QP7w5XUx3G2i39j/O68DtDAlaMKnaHIXdRcvauI /chajvnfTZC9bOHEmf6yvnxqhLrdnduIqhGme1IJymRzISFAz+gRZxm78gXBDQr3EeVA 9PP760TPtgUqwPxX/KfmsLe2JAze1SnZf1q16CijIO0/p9GYbX+RvhpB/xOfMeWPPeX/ e78ILPeVi7ttH4hHwj63yQA8SfOnsDTOJKVjLsbZyTrTNC2lNL7/Dyw/0Q60SD5AFVxK VVxQ== X-Gm-Message-State: AOJu0YxzAcg3fFUwYQW00zCr2SbbBcRqAEXp0LzXaxsXTu9aEjOnWYTc M+R/P//hazln7Q14YW4vcIrHhl26P2YPFMxEK63vEOFffLjbCVqdsrOqlf1d1Cg= X-Google-Smtp-Source: AGHT+IEumLOfgHy9ptSYIb80BMzk95Th2CfOVKwPVPTL9GX5qt4vT11e0BpVTPi3+WCx/rlRYbxNTg== X-Received: by 2002:a17:90a:e60d:b0:2c4:a7af:4d79 with SMTP id 98e67ed59e1d1-2c7b5c75d03mr5990223a91.11.1718906254495; Thu, 20 Jun 2024 10:57:34 -0700 (PDT) Received: from localhost ([216.228.127.128]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2c7e5af9b5dsm1989603a91.43.2024.06.20.10.57.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jun 2024 10:57:34 -0700 (PDT) From: Yury Norov To: linux-kernel@vger.kernel.org, Shuai Xue , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org Cc: Yury Norov , Alexey Klimov , Bart Van Assche , Jan Kara , Linus Torvalds , Matthew Wilcox , Mirsad Todorovac , Rasmus Villemoes , Sergey Shtylyov Subject: [PATCH v4 09/40] drivers/perf: optimize ali_drw_get_counter_idx() by using find_and_set_bit() Date: Thu, 20 Jun 2024 10:56:32 -0700 Message-ID: <20240620175703.605111-10-yury.norov@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240620175703.605111-1-yury.norov@gmail.com> References: <20240620175703.605111-1-yury.norov@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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 | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_u= ncore_drw_pmu.c index 38a2947ae813..1516f2c3d58f 100644 --- a/drivers/perf/alibaba_uncore_drw_pmu.c +++ b/drivers/perf/alibaba_uncore_drw_pmu.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -266,15 +267,9 @@ 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 2.43.0