From nobody Tue Dec 16 07:27:04 2025 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 05D5E221FA1; Thu, 8 May 2025 10:34:30 +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=1746700471; cv=none; b=r2gHGrLKkGNkd7TZSiO+AZo88y/sWKttXkhBLSPsbGjaB2tksG+cSTS0gq4eqMOgCO4v5qYQD8YuBWi7QQKA82InihpywQTX37qad3diDrtU1lX/ACrHVwHRthv8VOpvelg9u/o5ak/cxDWBwOw+RsxV/c3erUngcZ1oOnX/g4I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746700471; c=relaxed/simple; bh=5LiML9Ijqi/i3YhbwMzk6qGTWOXAVqGDL+6j0A9oL2I=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=tAX+l1Y1s5LUzmQzOIgZH4Ra7EQsGai8wD423EWLL/remRn7tHnexTrNTxRG9nNHevX6JN5NYBbTCxgg/BlYkcjStt4GbIEQMkYmwXzVU+xIHXBvrd5UHI2RXsYeaMpJEqgiKbDYAkjSkBhDqDGtsbu54mVzlfkA2dZscW1kGfk= 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=IzePWVWp; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=caONFTq3; 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="IzePWVWp"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="caONFTq3" Date: Thu, 08 May 2025 10:34:27 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1746700468; 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=NDSSoZ0GooGOAcSnrwig99WmPFQ3Q4NQkHSH3X8s1Hw=; b=IzePWVWpsi9jG4WUqciAxkVmcqAfDoTWOqdYzn7gzlBWZML4NdUDxE1lOha+fxeglRtTWK 5Uw+T2RCJSQGukUZPkeW6wejHQ28fD4cbJoF+lGZ6iKA9mqXbOjGebVBtj9EOgUyNue8DN 2sTAtZLgPG7Chu1XZVp/K1YmbcZkVH6Ja+eZ3I3vuf5o+GGUySAD5x7I1z5P2oUV1zus0n R4TEUUgAU30GdZFxWHBswfxjihOBTWzyMjhrkhdkWZRmT3kb2+IkzwXRkdj5CcZ18PNiU+ J7kpcN4SC4Ts1cjdRhNkXXZFpXED78PcVTuAvtZinNcXBi/TavCHKHF5Cb408A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1746700468; 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=NDSSoZ0GooGOAcSnrwig99WmPFQ3Q4NQkHSH3X8s1Hw=; b=caONFTq3kK5t7WBS2qICbxv6OZzb8UwFO3uB5Yn2PFwbeH/v//QR/sbL9zyk7ySVmekyHz Cx16JYvGd26b2LDw== From: "tip-bot2 for Frederic Weisbecker" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf: Fix confusing aux iteration Cc: Frederic Weisbecker , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250424161128.29176-5-frederic@kernel.org> References: <20250424161128.29176-5-frederic@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <174670046772.406.3650445834841658682.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: dd0987d6358ef52bac886c5fe8287c12f47a7656 Gitweb: https://git.kernel.org/tip/dd0987d6358ef52bac886c5fe8287c12f= 47a7656 Author: Frederic Weisbecker AuthorDate: Thu, 24 Apr 2025 18:11:28 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 02 May 2025 12:40:41 +02:00 perf: Fix confusing aux iteration While an event tears down all links to it as an aux, the iteration happens on the event's group leader instead of the group itself. If the event is a group leader, it has no effect because the event is also its own group leader. But otherwise there would be a risk to detach all the siblings events from the wrong group leader. It just happens to work because each sibling's aux link is tested against the right event before proceeding. Also the ctx lock is the same for the events and their group leader so the iteration is safe. Yet the iteration is confusing. Clarify the actual intent. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250424161128.29176-5-frederic@kernel.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 e0ca4a8..b846107 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2171,7 +2171,7 @@ static void perf_put_aux_event(struct perf_event *eve= nt) * If the event is an aux_event, tear down all links to * it from other events. */ - for_each_sibling_event(iter, event->group_leader) { + for_each_sibling_event(iter, event) { if (iter->aux_event !=3D event) continue;