From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 3E92F190676 for ; Fri, 14 Mar 2025 21:05:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741986356; cv=none; b=pW3misfsavRvuB76QcAb1/BkClgJ7XrOT6+/e4X7aK9axlc4HBvXBtQ7zAZD35vUv5j3MS1RFt8zd7V+BZ6O+Qk6CcySGmSbj5C0T7uu+/qMRUez93DOf58OROViJEG0Iu2PPeMNM2nb6TF4AWR18xbAD9Hq6a7UdM+/4dKOANU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741986356; c=relaxed/simple; bh=BGCvmQQoA6AZnAf+husQQwCH5fuFyt4lXeTQBEhYU2k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CvxUV8B+yZsQWlG6/0JCzvLm1H9HknUohxvy6S+oXLrTMeBRCEzvy3XPfJFuhaG8IbjlCjBpS/gnhiROjceyaflDPkKW2xEVOfW8IUT5wzHulXe3E1fIrHWQdXKd9WjnOxL5/orwLqYw6I8GEXnv+VnlBHT1Hdwl6KnC88nd/Os= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Mna+H8zA; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Mna+H8zA" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=mVsR1yStgTogjmLrRkPuU6O9y/i4nkeXIwo7Bc2ylNg=; b=Mna+H8zA/e07W6b5N2Eug1dbIa s4n7+FE9SSk76zlpl0BYEpAzCaQjv+t1+0g+aG5aZOkyaUF8KJEyBN8bMDYt6U0sLRT2+PAlzMRQb c+2Cr6OZZzzfMRooi8uVVX24MnlqjObkYEnybfXn+8451RsdbfI6aAR26UX9hkCAxJtWobz9KMXVV bQiHuBHL82U3xxPyIgOB8GhD4lcNqdw0ttkCAmygEUsPyuNTomUQWiZYli7xjqnInGStEO7z15Ovf rbYT9Z+XfHBR5gMU4s2L9saAfsWXktb1QUQcQ0vLDv4ahPbu6YB1qpSAGxKZJyOlRdQrLvP1dVJwb bPXVZjag==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1ttCDz-00000002wrX-00Cp; Fri, 14 Mar 2025 21:05:47 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 21597300599; Fri, 14 Mar 2025 22:05:46 +0100 (CET) Date: Fri, 14 Mar 2025 22:05:45 +0100 From: Peter Zijlstra To: kan.liang@linux.intel.com Cc: mingo@redhat.com, tglx@linutronix.de, bp@alien8.de, acme@kernel.org, namhyung@kernel.org, irogers@google.com, linux-kernel@vger.kernel.org, ak@linux.intel.com, eranian@google.com Subject: Re: [PATCH V10 3/7] perf: attach/detach PMU specific data Message-ID: <20250314210545.GB21786@noisy.programming.kicks-ass.net> References: <20250314172700.438923-1-kan.liang@linux.intel.com> <20250314172700.438923-3-kan.liang@linux.intel.com> 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-Disposition: inline In-Reply-To: <20250314172700.438923-3-kan.liang@linux.intel.com> On Fri, Mar 14, 2025 at 10:26:56AM -0700, kan.liang@linux.intel.com wrote: > @@ -5393,6 +5607,9 @@ static void __free_event(struct perf_event *event) > if (is_cgroup_event(event)) > perf_detach_cgroup(event); > > + if (event->attach_state & PERF_ATTACH_TASK_DATA) > + detach_perf_ctx_data(event); > + > if (event->destroy) > event->destroy(event); > > @@ -12481,6 +12746,18 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, > if (IS_ERR(pmu)) > return (void*)pmu; > > + /* > + * The PERF_ATTACH_TASK_DATA is set in the event_init()->hw_config(). > + * The attach should be right after the perf_init_event(). > + * Otherwise, the __free_event() would mistakenly detach the non-exist > + * perf_ctx_data because of the other errors between them. > + */ > + if (event->attach_state & PERF_ATTACH_TASK_DATA) { > + err = attach_perf_ctx_data(event); > + if (err) > + return ERR_PTR(err); > + } > + > /* > * Disallow uncore-task events. Similarly, disallow uncore-cgroup > * events (they don't make sense as the cgroup will be different I've stuck this on top. Let me see if it all compiles and push out to queue/perf/core. --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -666,11 +666,12 @@ struct swevent_hlist { #define PERF_ATTACH_GROUP 0x0002 #define PERF_ATTACH_TASK 0x0004 #define PERF_ATTACH_TASK_DATA 0x0008 -#define PERF_ATTACH_ITRACE 0x0010 +#define PERF_ATTACH_GLOBAL_DATA 0x0010 #define PERF_ATTACH_SCHED_CB 0x0020 #define PERF_ATTACH_CHILD 0x0040 #define PERF_ATTACH_EXCLUSIVE 0x0080 #define PERF_ATTACH_CALLCHAIN 0x0100 +#define PERF_ATTACH_ITRACE 0x0200 struct bpf_prog; struct perf_cgroup; --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5278,14 +5278,19 @@ attach_perf_ctx_data(struct perf_event * { struct task_struct *task = event->hw.target; struct kmem_cache *ctx_cache = event->pmu->task_ctx_cache; + int ret; if (!ctx_cache) return -ENOMEM; if (task) return attach_task_ctx_data(task, ctx_cache, false); - else - return attach_global_ctx_data(ctx_cache); + + ret = attach_global_ctx_data(ctx_cache); + if (ret) + return ret; + + event->attach_state |= PERF_ATTACH_GLOBAL_DATA; } static void @@ -5348,13 +5353,15 @@ static void detach_perf_ctx_data(struct { struct task_struct *task = event->hw.target; - if (!event->pmu->task_ctx_cache) - return; + event->attach_state &= ~PERF_ATTACH_TASK_DATA; if (task) - detach_task_ctx_data(task); - else + return detach_task_ctx_data(task); + + if (event->attach_state & PERF_ATTACH_GLOBAL_DATA) { detach_global_ctx_data(); + event->attach_state &= ~PERF_ATTACH_GLOBAL_DATA; + } } static void unaccount_event(struct perf_event *event)