From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 8C1C91E5B95 for ; Fri, 14 Mar 2025 11:01:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741950083; cv=none; b=aVl1zRJUaxBeC/ZNQlSt9PvHRmfRvWS7H0/+k5A0eixG0o8qk9C+Y2BUD6HDZhF4jby0rYMiLJJ9pnIB13Tb/koxCUCtiUTsgyfwmg4/zZsm2c+V8EeeC4ja58HglE+GniwS2nUtZtgE/R50Rg3nWDdFpTOxVMB9xc5P7NFyZaQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741950083; c=relaxed/simple; bh=wSrdNpvE6BBVdnL5Xg5M3p7VjhKgOqw4REV4qu72WpI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uTStD8TkHOcw3QUKaNWJcq2uHbEuiBK76PMVXuSxUH+47zcLCWdeHPaq0BY3b5vyIX8YRvyYQgCtM67punULfJmQZrNwRLMsGLDgaZIJiuKcpsXzoCi7ELxjjsJtzZaBMRCK0vscXag30H0pz/KeUaj9O3ULLkJ8McHjtqjwyhc= 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=T7hWzj93; arc=none smtp.client-ip=90.155.50.34 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="T7hWzj93" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=7isWwY/qpGnRrUm0sVQaVkG3yVbQ9GHkuVrefn9jIQo=; b=T7hWzj93s1A3hy1e+DsR7TqNmj am/n3Iur8yqbfHoVaOMGzw0zIEVp9Tpp5FAYetEYWRv36VRN6ANL7Ckt+9/GEWWpHH145L08kc5O2 DGCTxhkjy8NbibZPvGd48Xh7yc7jLLJGWJuNQ4av0uokEFZEhdxsZa4stuAyWWmCCHEFOUz8Xat4/ yuX7zekhbhXjENwnkva87kqxD4Xl1WEz0MroeiREHhD5iY4D0+q0db7pWR4Ar+V2Sc29flKLKrX28 28hCgF45VQxxO8BoGnmrc0ZRnE0QKKbkxS5qE45Ea2eZ1dSv4JWg46a8ariZb7tk/wEggA0lfFT3H /1cg7L9A==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tt2kj-0000000HLsm-42sE; Fri, 14 Mar 2025 10:59:34 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id D911A300599; Fri, 14 Mar 2025 11:58:56 +0100 (CET) Date: Fri, 14 Mar 2025 11:58:56 +0100 From: Peter Zijlstra To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, =?iso-8859-1?Q?Andr=E9?= Almeida , Darren Hart , Davidlohr Bueso , Ingo Molnar , Juri Lelli , Thomas Gleixner , Valentin Schneider , Waiman Long Subject: Re: [PATCH v10 00/21] futex: Add support task local hash maps, FUTEX2_NUMA and FUTEX2_MPOL Message-ID: <20250314105856.GB36322@noisy.programming.kicks-ass.net> References: <20250312151634.2183278-1-bigeasy@linutronix.de> <20250312151848.RlB_XuHA@linutronix.de> 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: <20250312151848.RlB_XuHA@linutronix.de> On Wed, Mar 12, 2025 at 04:18:48PM +0100, Sebastian Andrzej Siewior wrote: > @@ -1591,7 +1597,8 @@ static int futex_hash_allocate(unsigned int hash_slots, bool custom) > struct futex_private_hash *free __free(kvfree) = NULL; > struct futex_private_hash *cur, *new; > > - cur = mm->futex_phash; > + cur = rcu_dereference_protected(mm->futex_phash, > + lockdep_is_held(&mm->futex_hash_lock)); > new = mm->futex_phash_new; > mm->futex_phash_new = NULL; > Same thing again, this makes no sense.