From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E9A3176028 for ; Thu, 8 Feb 2024 12:39:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707395994; cv=none; b=PJrvxSqjC2jbk5c8cJJK2IeOVPbcCSGsKVTofm4Ho1wWbVgXFpIkhzPj6jgDu+jBQEf+oYULTMVWLEvKmYti7s+OvCSGTFDasBwI3YCzwSJCqqirUpeK+1M4pSOcOe3HAu7cL7WFhA4sl+ChDPqOrpOvG0hFxquZyc5754H5Hqs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707395994; c=relaxed/simple; bh=0hbCarOtP5u95JGe8C90Cgaf3YAyJNnkarhl9gvl9NE=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Q4I90tOAHJ/GoEqgYfhcG8ct/O+y2Gb4xLhAz/rmMocPOY1ioWLWddzxwUYT3RLyCCMji14rZYakj4wK27yF5DWYlBjM1YiPR9rvUQieLN6f/LNISgRpbuHnCiJ8eHsk+VZKrAPFVAPYKzrxr4ecXqygsCda4V5zp6qib/3pYso= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4TVxLL487Tz6K5pX; Thu, 8 Feb 2024 20:36:26 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 29D9E140D1A; Thu, 8 Feb 2024 20:39:48 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Thu, 8 Feb 2024 12:39:47 +0000 Date: Thu, 8 Feb 2024 12:39:46 +0000 From: Jonathan Cameron To: Yicong Yang CC: , , , , , , , , Subject: Re: [PATCH 6/7] drivers/perf: hisi_pcie: Merge find_related_event() and get_event_idx() Message-ID: <20240208123946.00006618@Huawei.com> In-Reply-To: <20240204074527.47110-7-yangyicong@huawei.com> References: <20240204074527.47110-1-yangyicong@huawei.com> <20240204074527.47110-7-yangyicong@huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To lhrpeml500005.china.huawei.com (7.191.163.240) On Sun, 4 Feb 2024 15:45:26 +0800 Yicong Yang wrote: > From: Junhao He > > The function xxx_find_related_event() scan all working events to find > related events. During this process, we also can find the idle counters. > If not found related events, return the first idle counter to simplify > the code. > > Signed-off-by: Junhao He > Signed-off-by: Yicong Yang A suggestion inline to avoid the magic HISI_PCIE_MAX_COUNTER value being used outside of the function. > --- > drivers/perf/hisilicon/hisi_pcie_pmu.c | 55 ++++++++++---------------- > 1 file changed, 21 insertions(+), 34 deletions(-) > > diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c > index 1b45aeb82859..2edde66675e7 100644 > --- a/drivers/perf/hisilicon/hisi_pcie_pmu.c > +++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c > @@ -397,16 +397,24 @@ static u64 hisi_pcie_pmu_read_counter(struct perf_event *event) > return hisi_pcie_pmu_readq(pcie_pmu, event->hw.event_base, idx); > } > > -static int hisi_pcie_pmu_find_related_event(struct hisi_pcie_pmu *pcie_pmu, > - struct perf_event *event) > +/* > + * Check all work events, if a relevant event is found then we return it > + * first, otherwise return the first idle counter (need to reset). > + */ > +static int hisi_pcie_pmu_get_event_idx(struct hisi_pcie_pmu *pcie_pmu, > + struct perf_event *event) > { > + int first_idle = HISI_PCIE_MAX_COUNTERS; int first_idle = -EAGAIN; > struct perf_event *sibling; > int idx; > > for (idx = 0; idx < HISI_PCIE_MAX_COUNTERS; idx++) { > sibling = pcie_pmu->hw_events[idx]; > - if (!sibling) > + if (!sibling) { > + if (first_idle == HISI_PCIE_MAX_COUNTERS) if (first_idle == -EAGAIN) > + first_idle = idx; > continue; > + } > > /* Related events must be used in group */ > if (hisi_pcie_pmu_cmp_event(sibling, event) && > @@ -414,19 +422,7 @@ static int hisi_pcie_pmu_find_related_event(struct hisi_pcie_pmu *pcie_pmu, > return idx; > } > > - return idx; > -} > - > -static int hisi_pcie_pmu_get_event_idx(struct hisi_pcie_pmu *pcie_pmu) > -{ > - int idx; > - > - for (idx = 0; idx < HISI_PCIE_MAX_COUNTERS; idx++) { > - if (!pcie_pmu->hw_events[idx]) > - return idx; > - } > - > - return -EINVAL; > + return first_idle; Then this will return -EAGAIN; > } > > static void hisi_pcie_pmu_event_update(struct perf_event *event) > @@ -552,27 +548,18 @@ static int hisi_pcie_pmu_add(struct perf_event *event, int flags) > > hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; > > - /* Check all working events to find a related event. */ > - idx = hisi_pcie_pmu_find_related_event(pcie_pmu, event); > - if (idx < 0) > - return idx; > - > - /* Current event shares an enabled counter with the related event */ > - if (idx < HISI_PCIE_MAX_COUNTERS) { > - hwc->idx = idx; > - goto start_count; > - } > - > - idx = hisi_pcie_pmu_get_event_idx(pcie_pmu); > - if (idx < 0) > - return idx; > + idx = hisi_pcie_pmu_get_event_idx(pcie_pmu, event); > + if (idx == HISI_PCIE_MAX_COUNTERS) > + return -EAGAIN; Perhaps simpler to handle first_idle == HISI_PCIE_MAX_COUNTERS as an error return in hisi_pcie_pmu_get_event_idx - see above. if (idx < 0) return idx; > > hwc->idx = idx; > - pcie_pmu->hw_events[idx] = event; > - /* Reset Counter to avoid previous statistic interference. */ > - hisi_pcie_pmu_reset_counter(pcie_pmu, idx); > > -start_count: > + /* No enabled counter found with related event, reset it */ > + if (!pcie_pmu->hw_events[idx]) { > + hisi_pcie_pmu_reset_counter(pcie_pmu, idx); > + pcie_pmu->hw_events[idx] = event; > + } > + > if (flags & PERF_EF_START) > hisi_pcie_pmu_start(event, PERF_EF_RELOAD); >