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[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: regressions@lists.linux.dev 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 >