From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) (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 E2A9F1459FA for ; Wed, 1 Oct 2025 15:45:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759333530; cv=none; b=S2THxEuEouzZI0pyQzWqfxruQrwxKLc787SUXl5eijy28WV7SGkzb4bm1sD9UhNzSGLwOL8437JSDl7fXPVcil5Vuwy7l5NELb5mRbwjAcikTfze0OY1f6xcHwWPdLLJ+2VfRIu6ghwIAfHOx6T3agDJR+od8p8z6A5Yc3wsjn4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759333530; c=relaxed/simple; bh=l3+j1qBtWVeJbLqlOoYwmRcgTQWLmfgBE3R7wFAstRo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=BBeBeApa/boXSkvRyYyX/QbrLogJvbb4w+Q/xngSSlgTVaa897fZLuPnvKrkacl+Au33DlePsPGl81dVC7/h4bddEDUzNhPWqQ0ZwM8ubYEtKjAXHYXSr6C95nE1M0FLr4JCi5ZEN8tqmcIMr5J9iEHNCKnTb1CMUcHIaFuMWRI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 6563BC0166; Wed, 1 Oct 2025 15:45:26 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf18.hostedemail.com (Postfix) with ESMTPA id B6A1F31; Wed, 1 Oct 2025 15:45:24 +0000 (UTC) Date: Wed, 1 Oct 2025 11:47:02 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: jpoimboe@kernel.org, rostedt@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 09/12] unwind: Make unwind_task_info::unwind_mask consistent Message-ID: <20251001114702.06e2b1d8@gandalf.local.home> In-Reply-To: <20250924080119.384384486@infradead.org> References: <20250924075948.579302904@infradead.org> <20250924080119.384384486@infradead.org> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Stat-Signature: g158948skhodmx6tbwzf39gubiss9f7d X-Rspamd-Server: rspamout01 X-Rspamd-Queue-Id: B6A1F31 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+OMW4XSFp4Dig02OXKk246amWPi9EXI+k= X-HE-Tag: 1759333524-461601 X-HE-Meta: U2FsdGVkX1/zVpPXzhVGhC4Y+71/FCLiJlnm/QiGd4rgK0kGR4FcS8p5zKH7IEMeqt3Dz4eZT85hCeB6PvfDKatZ9mkFGo8v9JBrEiI7oWnQLd0Bv8qvgE0wwgsjVl9mZNDSTkjGMHEHZJooLP1mL6JnrL1/aEipRUWB9WaWJF0bGfiOgVuz9K4/++CITy51cPeHkHQPHkb6KFUzAYViQ1KKLdLwHJqWPVVLn6vw6zYPLPPfRv4g2A2puKTgdNUiHLxjiMl+umRAiPv8KXF+p9nfcUXA6jnzbNKh1g4X/auUg2lbU71+MwXPQYVeAf6TFzympqBbpiuEdXALRevRDTy7HZHKkMguNaMzZb9SO8LbGZjp8TfT+HB34EhyY+44 On Wed, 24 Sep 2025 09:59:57 +0200 Peter Zijlstra wrote: > @@ -324,7 +324,8 @@ void unwind_deferred_cancel(struct unwin > guard(rcu)(); > /* Clear this bit from all threads */ > for_each_process_thread(g, t) { > - clear_bit(bit, &t->unwind_info.unwind_mask); > + atomic_long_andnot(UNWIND_USED, > + &t->unwind_info.unwind_mask); Shouldn't this be: atomic_long_andnot(BIT(bit), &t->unwind_info.unwind_mask); ? As BIT(bit) != UNWIND_USED. -- Steve > if (t->unwind_info.cache) > clear_bit(bit, &t->unwind_info.cache->unwind_completed); > }