From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 25B9F4A64CD; Tue, 15 Sep 2026 14:55:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789484117; cv=none; b=IlR2zyeJMa9EAB8GmxM/v4OTPVjaAUZsGsCP7Nn/mdjvnIEhGxzcu3/JHfkiRx45qYxHtyhAAjcaUy9R+BhxytifKU9wu4+J3HlqdCBs40k/L78Ey/gHA51egdhP4ZLhwI35B3nAIAR30FcSaSIWWnhH3Y8AmExuBv5BV47uqbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789484117; c=relaxed/simple; bh=ocvrlDniUILB2Qn+xpcxcG1bxect9rksUAFthAjrYUk=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=dfYZyEnCygVKBrCwGpNXgroGsazVOnAHYbuchiW7VYB62yCBmsc4j+i7t8lNrcU3Xk+FbIX7yMNlqP5gIMf7XYPsubkvb6OMkI6GyM0awt18nsbuK77iXfBdcQPdDY62YdiggTEsObLUcW52amehLXwl2yAs+PlXf2DtNSUBV/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aqz0Aaof; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aqz0Aaof" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D0E61F000FF; Tue, 15 Sep 2026 14:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789484104; bh=D1Mmk5fSxyhosignrfJbyzO5uMwrwmLvAMFCvEMPdKM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=aqz0AaofVPDlRQvBjaVSYXT95+pstzVvSszXgFIdf4Pm4StLb2F1nYMx4pC7iiS6p bjJfNAMyvtEKLxgOE1nAIDRXoIAE80Eq/i/9W2lxZHjkvKDTgDdUFpS8wUNr3fAg2E qGNp7gFuHQuCjVdAefDtX4zJKhGgifcXcUJmykC2K2dyAsaV4Jx/FAwlxpZY9BrVK+ VErhNpBmpaQWZGs5PHLJ+jxtx2djxPoelcCIqaZ5pWudVOVs5IpYxGthIp9lmoi7rF kr++FjT5v+HrurSRGW554x71x8B+Egx8fHlBC1YF8ugODc7enPpQxjFZ6pS3sgVtBd ey1UtLNdGLWuw== From: sashiko-bot@kernel.org Subject: Re: [PATCH] s390/uv: Rework page allocation for guest variable storage area Reply-To: sashiko-reviews@lists.linux.dev To: "Heiko Carstens" Cc: "Alexander Gordeev" , "Christian Borntraeger" , "Vasily Gorbik" , linux-s390@vger.kernel.org, "Heiko Carstens" , kvm@vger.kernel.org In-Reply-To: <20260915144307.2367089-1-hca@linux.ibm.com> References: <20260915144307.2367089-1-hca@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 15 Sep 2026 14:55:03 +0000 Message-Id: <20260915145504.2D0E61F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Alexander Gordeev reported that the allocation of pages of the > guest variable storage area via the uv_alloc_range_cb() callback > of apply_to_page_range() will cause problems as soon as s390 fully > supports lazy mmu mode. >=20 > Problem is that uv_alloc_range_cb() allocates pages with GFP_KERNEL while > preemption would be disabled. This would result in reports like this: >=20 > BUG: sleeping function called from invalid context at ./include/linux/sc= hed/mm.h:322 > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6092, name: qemu-= kvm > preempt_count: 1, expected: 0 > ... > Call Trace: > dump_stack_lvl+0xae/0x108 > __might_resched+0x1de/0x2f0 > [ ... ] > potential future bug. >=20 > Reported-by: Alexander Gordeev > Closes: https://lore.kernel.org/all/e9449c63-b8d2-4ed9-a184-7dcab3e8dfce-= agordeev@linux.ibm.com > Signed-off-by: Heiko Carstens Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260915144307.2367= 089-1-hca@linux.ibm.com?part=3D1