From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 01C8D29B233; Wed, 12 Nov 2025 21:54:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762984462; cv=none; b=DOjzT2K9g492MvmPRdJWSFmWDbURYP/eh6TN6iXvTCwyKHrbzCK34UA6ukECcUegWfq6QxiHLinI3gu8xcbAYnMXCkZ2t1AMshDabekajWY18YCeYhbmvBnm5kYEVDI/7oHznliK5yhIvn7uWj30GOW+jhkOXn+sBRF6i1ckKlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762984462; c=relaxed/simple; bh=vy3Z/BpNW0xbQ8hrd2pZdbCa6OqDrTid72iM3mZurgg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=mulnlDw4zWPyYzBapPgEkOXZ/pE4MwAqyqkS8U9tMRYAj80nIuv43T/aRwJ2QLvAJzRzXpLdZuVGTdoHJi5Gsp6KKBMwyOpjsCr+2N+2E8SRnSUkNulN2nzxnC2ZehSbqzLQNXNRp+lr6b8wAToIy9kB5Nu1xwlbIq0qshSKNCg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=L2oTveuv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Cj8Goiph; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="L2oTveuv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Cj8Goiph" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1762984458; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vy3Z/BpNW0xbQ8hrd2pZdbCa6OqDrTid72iM3mZurgg=; b=L2oTveuv4TT6Z4Tv85GCjyU8tzmbQNPg+gX1ahkdehAnWw3J1PccS6AR5HbjhOk1pqoYVT +Vnk84fkk4BylnRu6lZGQ/sxUeIT6VV7YN83c6Gq17rUaWm9F8dAOMvCNXln641jVgZKgm JOe+nWDRBsDzqPL3oOgjGl8WWBAMbANxEScDsEoojT232si/eQwShlLZlP1Jo5glZS/gJJ YPDft0TBU5f4VYDU2rjFDgEfUvPDTD7Ik7YApQCYo4bizwFpx0wZ9N9RB32zTqDoZFK2GB ufyeGkqMU5YH0No38GkQwcnIzIIwpjUo2YXPBkcNGlwty9yWqGwB87LlR9lBAg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1762984458; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vy3Z/BpNW0xbQ8hrd2pZdbCa6OqDrTid72iM3mZurgg=; b=Cj8Goiph0lJvbH3un95layiWPGdUSvnc1HwvbMVVfsnCE9jUYvyQWYnf1w8bJZtxVYyhdD n0slSrxXGvFp2bDA== To: Mathieu Desnoyers , Prakash Sangappa Cc: LKML , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Jonathan Corbet , Madadi Vineeth Reddy , K Prateek Nayak , Steven Rostedt , Sebastian Andrzej Siewior , Arnd Bergmann , "linux-arch@vger.kernel.org" Subject: Re: [patch V3 00/12] rseq: Implement time slice extension mechanism In-Reply-To: <3a0f1467-7fff-48c6-b0d1-772917cc6143@efficios.com> References: <20251029125514.496134233@linutronix.de> <03687B00-0194-4707-ABCB-FB3CD5340F11@oracle.com> <2eee5e37-e541-4ac7-9479-cef3e62f234d@efficios.com> <87ldkbdmbu.ffs@tglx> <3a0f1467-7fff-48c6-b0d1-772917cc6143@efficios.com> Date: Wed, 12 Nov 2025 22:54:17 +0100 Message-ID: <87fraiex2u.ffs@tglx> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Wed, Nov 12 2025 at 15:46, Mathieu Desnoyers wrote: > On 2025-11-12 15:31, Thomas Gleixner wrote: >> I did not notice the V3 issue because tests passed on a small machine, >> but after I did a rebase to the tip rseq and uaccess bits, I noticed the >> failure because I tested on a larger box. > > Good ! We'll see if this fixes the issue observed by Prakash. If not, > I'm curious to validate that num_possible_cpus() is always set to its > final value before _any_ mm is created. It _is_ set to it's final value in start_kernel() before setup_per_cpu_areas() is invoked. Otherwise the kernel would not work at all.