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 D70161DF735 for ; Mon, 28 Oct 2024 17:50:12 +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=1730137815; cv=none; b=dV/jkLYlZU0WBgYU8yejKctuuZKQErOFzW7Z6EqOMapJpwxjgMTaIcOrT8XD24xUMYGtydTOAL/PIzJHaF9b0Ep3XPB4fEaWwKNRhtAdgC1uCk7lR0zZjXKAz58bUurT52+oZCixiftLzDim2XgQc6NJfZJud19GAL9snFnvcV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730137815; c=relaxed/simple; bh=am9FmeupZaSwxqmhev2j2lFZGvkVdGdy2c0oNmEN1FE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=t66UPcBuKiNXViSzdE1NMykTu52QgOTcSP++jGl5qkZBVM3XIsKhnVIfYAdAwiS9jFsoPFyoRXU08KyaPVOTnGh/ckSNkh5bOxH+rFBJboUAamEU5O7SLRv5gIm7fMw/fyJ0DV6cRuRJNbsXFunYdAw/FzOffOlXWdN7AvpECOI= 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=uVTPVvCz; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=rDZ2YPNB; 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="uVTPVvCz"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="rDZ2YPNB" Date: Mon, 28 Oct 2024 18:50:08 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1730137811; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Uablt6bygIdi/EqgP/WcAcr3ykXK7+q/9dJRlPm3vRQ=; b=uVTPVvCzLuSI5qgw1ByMFFUzWeyBMQjS0MrqQEaZPgQUdyZUu97wzfksirDdRXQhfy2qK/ PIzLDIYcmYuwPDjLs3OAoDq/FU5dejwO/KOpZKKZtkytFFzDsCkNBWR3Y2DDxQ9NtXOCyA Pk3sDD3+MpqcVT66Q8Id+BjwQT0lbz9T+cB9PcpI3QoijQgLvKPuLHal2zOIeFCdV3f9QP IzdEySOPcuWivELHTsM45zdihuMI1wpTMdx1g3VNtp/B2FwyMRTbhBq/LykuyMT1TB8xCS JePaUjbnf1T65XIKUqdiCIROdBMbfrepPLoapA3XJL6RUrD/4EzPv2f2rcDzqQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1730137811; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Uablt6bygIdi/EqgP/WcAcr3ykXK7+q/9dJRlPm3vRQ=; b=rDZ2YPNBCM6WXzKa7nk/GVlu9dLZtinBegi8U3hQtwJteyYTuy90ERDRVRrSLRP8Gg4v6t SNcQZL4HMOv1uABw== From: Sebastian Andrzej Siewior To: linux-kernel@vger.kernel.org Cc: =?utf-8?B?QW5kcsOp?= Almeida , Darren Hart , Davidlohr Bueso , Ingo Molnar , Juri Lelli , Peter Zijlstra , Valentin Schneider , Waiman Long Subject: Re: [RFC v2 PATCH 0/4] futex: Add support task local hash maps. Message-ID: <20241028175008.lgdGYYtp@linutronix.de> References: <20241028121921.1264150-1-bigeasy@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=utf-8 Content-Disposition: inline In-Reply-To: <20241028121921.1264150-1-bigeasy@linutronix.de> On 2024-10-28 13:13:54 [+0100], To linux-kernel@vger.kernel.org wrote: > from time to time and I haven't seen it using the hashmap. Need to do > more testing. booted gnome and did a few things: - Total allocations: 632 - tasks which never used their allocated futex hash: 2 gpg-agent and systemd-journal - Tasks which did not terminate within the measurement: 85 This includes gpg-agent and systemd-journal - Top5 users of the private hash: - firefox-esr-3786 used 215985 - gnome-software-2343 used 121296 - chromium-3369 used 65796 - chromium-3209 used 34639 - Isolated used 34211 This looks like we could attach the private futex hashmap directly on fork instead of delaying it to the first usage. Side note: If someone is waiting for a thread to exit via pthread_join() then glibc uses here futex() with op 0x109. I would have expected a private flag. Sebastian