From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 16C801AC884; Fri, 1 Nov 2024 17:41:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730482882; cv=none; b=bilkf/mUZAn/YubGClnw6huci0KKfRuRU709tggfi/LomYcJc1hfqp4p5sAo2erqyATefjEqLRxUAQTXZ4CGQq6IR+tqrwh+r4VDTxbnLezqiHp+GH8m6Gsaz3OrI8fkEHk7oSNdb5S1cxEohAJXiZ9SX8bNseZJKtT+Ibg9nJQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730482882; c=relaxed/simple; bh=XeLsmqqTc3tYnHi81CpCxpoUam3VFymyrAfk9PaJZ6k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=EWiMapD3HXO4C/+lUn8lFm3AKYJiVGRm2nktl+YpYr5ayGPcs4eQHH2B3tHlqTritOokzmNRb090xKp5F8MOoDs0H6g7Z44cw0mY8fOmnDBE7t/G5lLFOUnHCzZmZgoz+DkTvAAf8BUdFLUJUZ8S226awA/akc7YAfuIuc10C5k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OYHzKctO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OYHzKctO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6CE6C4CECD; Fri, 1 Nov 2024 17:41:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730482881; bh=XeLsmqqTc3tYnHi81CpCxpoUam3VFymyrAfk9PaJZ6k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OYHzKctOz0p2FFBtqGmfIcnL9+kIiQCHrpWgnI+ZuYHgzh0AsZfKZQBvrRdO1fhPU 7aWYTGS6o6S6d5WhiCoWVAV5SqSeYx4wXc3cl72CE2adtfQR0oNg44OVdl8m9FXls0 t/ttz/EvkhjSixLVn6DBcPdfUDOpzLFjDj3kqvaGCTLCw1mphQJKrcU6qr2xBGP+p/ DQjq8SBTmrJPpR7Bb5rf4LoQldszghd3IaDeX//74fKA6bfHriJtyPPXjYg1wnXBeB HpgmjH3Kk3fk5Mj1k/MIgQijxZp40pRx8lOEUB0gL023ZuBR+XEGB8ZVPGZbFGZ+BQ urAfK3N03bSXA== Date: Fri, 1 Nov 2024 10:41:19 -0700 From: Josh Poimboeuf To: Andrii Nakryiko Cc: x86@kernel.org, Peter Zijlstra , Steven Rostedt , Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Indu Bhagat , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org, Jordan Rome , Sam James , linux-trace-kernel@vger.kerne.org, Jens Remus , Mathieu Desnoyers , Florian Weimer , Andy Lutomirski Subject: Re: [PATCH v3 11/19] unwind: Add deferred user space unwinding API Message-ID: <20241101174119.qso5fdln2chdflav@jpoimboe> References: <20241030061043.eo2vuqgsoqmjytjr@treble.attlocal.net> <20241031231320.h2hwns367e5byvyy@jpoimboe> 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: On Thu, Oct 31, 2024 at 04:28:08PM -0700, Andrii Nakryiko wrote: > So all task_structs on the system using 104 bytes more, *permanently* Either way it's permanent, we don't know when to free it until the task struct is freed... > and *unconditionally*, is not a concern Of course it's a concern, that's why we're looking for something better... > but lazy GFP_ATOMIC allocation when you actually need it is? We don't want to dip into the GFP_ATOMIC emergency reserves, those are kept for more important things. Actually, I think I can just use GFP_NOWAIT here. -- Josh