From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f41.google.com (mail-wm1-f41.google.com [209.85.128.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D24FB3EB7E8 for ; Thu, 18 Jun 2026 10:32:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781778756; cv=none; b=fB81RDUjbij6w4iawA2FA5qDIIDrYd+ToyVqqClWWxU0xDxF0fE7QeGPbsUCel7WJofg1rhk4LUSaHLQVbE9w3hBlzhWaKAhIBGgRNr7KXutvifpTItuxZwj+7iDpJIjE6/L8Hy1f+UwgMsDu0FpxO/3W0aW9zuhJmftdIg0Uxk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781778756; c=relaxed/simple; bh=vwsitVN7ozdKpgBSF4h9WVQoKxMhPysr7paPs2RYr+E=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jQ6jJ9m1weh3wjjM8LNgdR+pm/9c659Mk4tM7zLo9N25kXh/gy0kKNnchxDoFrXhkGOMLjxbTtuW4JtvmMj/EM+TrRkoaVxOMJAGKn5HfSCuhm7c2Qeaf9V6e1fnChIOIsmHONpo+JyqByqU8dZEXhXoeAZ90J4AZiS7PLVtUlM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=h+DDYPXd; arc=none smtp.client-ip=209.85.128.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h+DDYPXd" Received: by mail-wm1-f41.google.com with SMTP id 5b1f17b1804b1-4903d730b1fso8612315e9.2 for ; Thu, 18 Jun 2026 03:32:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781778752; x=1782383552; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=inqN7YwVEl5wZ+Codcae/bocVL29CD4f5KlLdUvEZRU=; b=h+DDYPXdELq4WUnUUb6ifz6APZOpo8FXcIml8fZ9HUcx9JY3BXSqKNSCN4kfnmGMPG S2Z+sPI3OukOFOqXO/E7Jb00lBG3BJmOJJnnRo/ML1KstJ4Msnh+LN6l1CdyG4OGxlAR kMbog3ALjm5/uD8vjQhcrxEkuG3RmiUcckafjcjG+K76RbXpeh0cHaJ/6xXUHFs2tWIg +U0o7JAOvUTKMTEmmygbAOtJ5uHgMeiyjVvwUdphLBefn/ZT/c/hKtRsoslbP/VkG5E7 KuQ6v9yEz3+o+9RpqiOlIbTq3aCG7NQ/u49WNeTVIc7ZQBfkk8KufC/V56nIB00i2Inc IqYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781778752; x=1782383552; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=inqN7YwVEl5wZ+Codcae/bocVL29CD4f5KlLdUvEZRU=; b=OnpyWO8RfBHAjKQry6wYmKuQgK3iZlhPsuL//b9/GrnxRHh6vzLNpyc5amJ82/s1p9 /GT5LXi2RJuDOVSK5zE99zVry4vNGmud5MbPie41xtMYdBuXs7dehAkWyz1TIMfS3hI5 K3yOXsrw9sTrAJaylcoT3QWnqN/OI3j35IKh68oRMhC/giG2DMcGrPPygRcgFtVSPsBR BgCUvYOZZCRg6264yuUf6vviXD7hKBFMw1jnlABl9A58OTgwioyLdV244R68qE9BHoEa X2woZ9eMM4gQ8MypAjVYgZAv/kBkX4UkqS1L8b/1T623cIrSgDKV2eTwB+V1b3FJoiCT b95Q== X-Forwarded-Encrypted: i=1; AFNElJ83ZczMsUR2VZ02Mmhau0y6KW+tZ1+gHLh6WAf985mN29xs8lbRbqxbg1l8kb3aqyScA0DJL1xfVR2gNZ8=@vger.kernel.org X-Gm-Message-State: AOJu0YwIrVnGlW0kOt723VNYnE82Ieo3ZuvRpaRrbjkcy/uVZgM4vcY8 y6itjvLwM5f/V7ea4em5Hmvu+X1G4OmIT5KDIbFVsWUKIh59WFBC5W3s X-Gm-Gg: AfdE7ckKFeFmaZ+Bdj8Xs7aBR04s4ggB6SLZrOly7c8KS2Xl1pEAepC2Kf5Lh9iVnJQ 931cdOULHv8AtDy39WY5lW8zRpXnvc2B6u6AUEBi5UmcKXldXq27qsttooPb5GoMT6OEAksYIXU 3rs/u0Toyxt8SDS1QYYQeeiSG2c6oXOlQr+nVSymYmeTFHymKQv1lXwrP16c7lOpjtQB9tKgnLY IDEJ4FzibcJhC61s1ZCT3JQieY62HmgmXe8ttINT5/mn+oSKRh1pfuo6Hdfvbwb81fnFwHED+Ww iya8SUS7eY+rBOpJFpkSSPtws8KFBYTO8j4LxKBHR+KqK2VIcxqnvOGX6IGNYGCRC6zNMiB2o2U 6b5vW0Li/zdaLi95UGlhgsf1NaEr9dsQsTYlIyjeaoUcZI2TkkR/aYoSA652V8L9TFFk3+Iu+a0 Zz5qx5+GcU3DCAnVbDgOmH24/tNPG3GsFrBEfnd61TKgGJaGNFxIb6B4p3Jso0 X-Received: by 2002:a05:600c:e547:20b0:490:3c15:7146 with SMTP id 5b1f17b1804b1-49238226380mr33567315e9.19.1781778751719; Thu, 18 Jun 2026 03:32:31 -0700 (PDT) Received: from pumpkin (82-69-66-36.dsl.in-addr.zen.co.uk. [82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4922fa3a4easm266778845e9.3.2026.06.18.03.32.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Jun 2026 03:32:31 -0700 (PDT) Date: Thu, 18 Jun 2026 11:32:29 +0100 From: David Laight To: Andreas Larsson Cc: Andreas Larsson , Tony Rodriguez , davem@davemloft.net, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, thuth@redhat.com, regressions@lists.linux.dev, glaubitz@physik.fu-berlin.de Subject: Re: [PATCH 1/1] sparc64: unify thread stack sizing and add explicit 32KB stack Message-ID: <20260618113229.7f1e51b3@pumpkin> In-Reply-To: References: <20260519075809.8993-1-unixpro1970@gmail.com> <20260519075809.8993-2-unixpro1970@gmail.com> <03111ac5-0055-425f-a7f2-54d4f2bb4988@gaisler.com> <20260616205851.428ca70c@pumpkin> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) 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, 18 Jun 2026 07:53:02 +0200 Andreas Larsson wrote: > On 2026-06-16 21:58, David Laight wrote: ... > > That whole logic is impenetrable. > > Why not set the 'desired thread size' in kB, then work out how many > > pages that ends up being based on the page size, and finally get the actual > > stack size. > > I'm not sure, but with vmalloc()ed stacks and 8k pages can't you have 24kB? > > No, the next step up is 32 KiB as the stack allocation is sized by > THREAD_SIZE_ORDER. Maybe, but there is probably no reason why that has to be the case. I'm sure I've seem other architectures increasing the stack size by 4k. David > > Cheers, > Andreas >