From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 2A9FC28504B for ; Wed, 10 Sep 2025 11:59:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757505551; cv=none; b=E0dSAthAs55k10jSk1b8uiuUQDAGInwu8Au18Bqhu9aU79cAv+xAEiIwX2f64yFE0Nv5bdw3XkNNQ/OJ/icE7pglRQT8dKBM3Nx5J0msTQVy/BIfASEWfFL/ahtGzJv3Ecz+oiwQfLjtjwyDbf6CJGFUSd61Rm/g6ZzWrG/glfc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757505551; c=relaxed/simple; bh=OySP/ewzDP7qYoXqik2jfMmlTSWEYVQiB3tXcLsIXio=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=qVrKgk007gWBXwsieoHFYZrQmcZM5YNwHhBEnoFpK6Ur8Ubd7zYP/1bw1bVxwwdcG1Ebw9Y2F0nJUg05Q8zoU7Fu3NOhWP69YOLhalBE1oA9XmsWlZ7B+Qyqe/7oHo1E+3kE0paaZx8p4Y7lsCeJVuUWDFhZft3kJCJMTQH43bs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=wiSnBkBY; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="wiSnBkBY" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=OySP/ewzDP7qYoXqik2jfMmlTSWEYVQiB3tXcLsIXio=; t=1757505550; x=1758715150; b=wiSnBkBYwa+50/p8jh4IcTFNGOxWKzU/lrGFveaYhb1NH0g Tn2McFc8/HHgvfX/qmDTwIBaVJSA802N9GyQ/pquoPnu+bE+4FIHnC/VtMjcyHBJ1cv1ZGVPejexR PYtRIV7R2h1y1RQ9Q6P4cxe4Vzj2JrcTMFadGHnJcCskpgOCuq9Cc7vFdEwB0+MCf0dbauDqkrSor tgnMOezneZuG+FvR0PEaxT11EH661/pY3DXdlEQo0KRKEJJqErFaJnOhv7TOeAEikbPQR3rjnby+0 UB7Ie2/PxtHbcXfPPfX1pADVU/DXlYAUxyEcqeMklap4B/FbsLPEKAdCteGp4HmQ==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1uwJTb-0000000CnNR-07Z6; Wed, 10 Sep 2025 13:59:03 +0200 Message-ID: Subject: Re: [PATCH v2 03/10] um: vdso: Implement __vdso_getcpu() via syscall From: Johannes Berg To: Tiwei Bie , richard@nod.at, anton.ivanov@cambridgegreys.com Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, benjamin@sipsolutions.net, arnd@arndb.de, tiwei.btw@antgroup.com Date: Wed, 10 Sep 2025 13:59:02 +0200 In-Reply-To: <20250810055136.897712-4-tiwei.bie@linux.dev> (sfid-20250810_075310_514820_7C2543B7) References: <20250810055136.897712-1-tiwei.bie@linux.dev> <20250810055136.897712-4-tiwei.bie@linux.dev> (sfid-20250810_075310_514820_7C2543B7) Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Sun, 2025-08-10 at 13:51 +0800, Tiwei Bie wrote: > From: Tiwei Bie >=20 > We are going to support SMP in UML, so we can not hard code > the CPU and NUMA node in __vdso_getcpu() anymore. Correct. But does that mean we actually have to implement it via syscall in the VDSO? That seems a bit odd? ARM doesn't seem to have getcpu in the VDSO at all, for example, so could we do the same and just remove it? johannes