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 5419FEDC for ; Sat, 1 Jun 2024 00:38:24 +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=1717202305; cv=none; b=K1CGsHDPAMKk8FzFIUgE/aYK7DAPv12jo4t4B73MMbr4DSD0ShB+q15AjY5AMdQvUSH0wQILYC7EuvSE0A0IvTWpVMtOTVYLrUC4udbOs6uDn5iTVNxleEGO/LZYI+Mds8FU2OugrpOwmDbRdlTRY6AB6PzaNtw4Gui1HERKx7E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717202305; c=relaxed/simple; bh=4hmjM0UxydhUZza82YHCth9Sj1TFopzUWYdExi8Y+ps=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=WOj7m0qFjlZ7ORO+ArWxzq8KqEEG1gvTOHGs0eGY71vhUm04zLS4CUfa4ZpnIj3JrH0uujlEkbVxdL3gDosKbSu6EJSTvhwY/msxIU8Lo62I6hkCenSpj7k5PNOQ+7Gofk6osKAqSMbPEFqhzdM03L9DsfphTZg7K3TydgMc0UA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=XEPfHq95; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="XEPfHq95" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4326CC116B1; Sat, 1 Jun 2024 00:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1717202304; bh=4hmjM0UxydhUZza82YHCth9Sj1TFopzUWYdExi8Y+ps=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XEPfHq95tZ1aJQMXPja1E8IqZy4rexHmWp0iBOOB0OTCFho8Ql7VXEbGMzYigg3hd JjHiPLp3BFSTHPZwBzry59vy+fTxRAuDunP8li0et+GKwmB8ZgG8lWdyZ8DPubGIA8 Em/a/V2spFlZopuIqcVPUKi2KOCXslvHZ3Q10FLM= Date: Fri, 31 May 2024 17:38:23 -0700 From: Andrew Morton To: Pasha Tatashin Cc: Shakeel Butt , jpoimboe@kernel.org, kent.overstreet@linux.dev, peterz@infradead.org, nphamcs@gmail.com, cerasuolodomenico@gmail.com, surenb@google.com, lizhijian@fujitsu.com, willy@infradead.org, vbabka@suse.cz, ziy@nvidia.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3] vmstat: Kernel stack usage histogram Message-Id: <20240531173823.4ec7b4693a4e433b1da91e75@linux-foundation.org> In-Reply-To: References: <20240530170259.852088-1-pasha.tatashin@soleen.com> X-Mailer: Sylpheed 3.8.0beta1 (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 On Thu, 30 May 2024 20:14:17 -0400 Pasha Tatashin wrote: > > Couple of questions: > > > > 1. In future with your on-demand kstack allocation feature, will these > > metrics still be useful? (I think so but I want to know your take) I do think the changelog for this patch should reference the dynamic stack feature. It strengthens the justification for adding this patch. > It depends on how on-demand allocation is implemented. On hardware > that supports faults on kernel stacks, we will have other metrics that > show the total number of pages allocated for stacks. On hardware where > faults are not supported, we will most likely have some optimization > where only some threads are extended, and for those, these metrics > will still be very useful. Also useful changelog info for this patch. Pasha, could you please prepare some additional text which I can paste in? Thanks.