From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 34849310781; Mon, 18 Aug 2025 10:22:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755512545; cv=none; b=oh2pcUqS/wN1f2J+9JGQ5saf6SybjJT/XwfLcJCwToc5MeUT0DHoqZ+u5s6k7UWec5OtKo+qItrQSnj4B0KeuY99EWJ9w7iauRsgcADPYXepsDjYFuzYcu/uzSpWhkUu8xUwz5TRi9PRIVH8eTjEVmN3WTiXce1WSW9oRif2sqI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755512545; c=relaxed/simple; bh=m3+kPG7phNOUIlkygU89zmX/g5b0e15Y2Xw1s3+WoS8=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=m6yBCteYiZvGZmhCJaN8LIqoiBIY96aUXVgasiuFIxldREqv68FdQ0pARhZPAjtWakA0+xgSF0h+1zvyvXjn5xW7ua3qaUSwodtLdU0req0JP8hZQV32IEeLPF0cdffmSENzEpmYYTUoixcZxr0rovqrmW1Zn8NUuWWGRLEucrc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=qAZukk4S; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=4Y0LLpay; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="qAZukk4S"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="4Y0LLpay" Date: Mon, 18 Aug 2025 10:22:20 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1755512542; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GIANA1wkLnraFp8iJSufp9XkMQsTV+JL5aZ0B38MVn4=; b=qAZukk4SbEv/PLPrQGjJVvftqCSp2J+IBy9K7B9DqDirIA5h5xcVRyN/lQhgHn0sTLKO/0 sLIIRxZbErlnDoJ72XwjC3f3AdrrgZJniay1jPz3aHpEpDOZE707dwO6uzynVHKnuERrro fCEClBAHZD7fFFEd22yge/b+hmf+4NMSpufdtfCKvZNO0WT9je9dTaJwT4r+ycbiTojNI+ Y1RAGuRp0P3oFNQgPb24Lc8Y4GFpvGr5inCKM8k73nanNdQ2/mz5+VAt7r4tqdr1pG1QW3 Wlco4po30c7TkG32nB882/gcCt7yAoupj5mtRLtOF3KVJyDZX6TJjpUdA6nUog== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1755512542; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GIANA1wkLnraFp8iJSufp9XkMQsTV+JL5aZ0B38MVn4=; b=4Y0LLpay8MOSXZx6DeGk+9jUD5v8zlKKNaB62vCbG2XkjIUIdlKYwp29XnMZraebjH00pd nYPRPqDRF/ObZiAQ== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf: Identify the 0->1 transition for event::mmap_count Cc: Thomas Gleixner , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250812104019.956479989@infradead.org> References: <20250812104019.956479989@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175551254020.1420.9814271943292016323.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the perf/core branch of tip: Commit-ID: 59741451b49ce9964a9758c19d6f7df2a1255c75 Gitweb: https://git.kernel.org/tip/59741451b49ce9964a9758c19d6f7df2a12= 55c75 Author: Peter Zijlstra AuthorDate: Tue, 12 Aug 2025 12:39:12 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 15 Aug 2025 13:13:02 +02:00 perf: Identify the 0->1 transition for event::mmap_count Needed because refcount_inc() doesn't allow the 0->1 transition. Specifically, this is the case where we've created the RB, this means there was no RB, and as such there could not have been an mmap. Additionally we hold mmap_mutex to serialize everything. This must be the first. Suggested-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250812104019.956479989@infradead.org --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 41941df..f6211ab 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7034,7 +7034,7 @@ static int perf_mmap_rb(struct vm_area_struct *vma, str= uct perf_event *event, perf_event_update_userpage(event); =20 perf_mmap_account(vma, user_extra, extra); - atomic_inc(&event->mmap_count); + atomic_set(&event->mmap_count, 1); =20 return 0; }