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 01A921C862F for ; Sun, 28 Jun 2026 06:55:13 +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=1782629715; cv=none; b=aeYcgnv/2w6YSDjb0pt0pf8afo0LGD0rWJwtftDUz99I49giYgc3cESBMKnc6qKjMyzK0rQN3xundjAM6mB3nqNEhLQRqJEhvo+G7IT4SkNHLDSfXcafAu/DwF0AXqF9qL2mNTJ4LrlSdrur22n/Rak7eSDmxBYpAi9rHnFRjno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782629715; c=relaxed/simple; bh=ZNu5uT8kM2JA9G6usVBTg9j0RugDgXIAqgzMED6yBag=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=fUzp9JgHN8ejv5Z6dpuUXEjaLN/LtvDm8nEaY39oPV99GvwZ1w1SPu7TLA25Mb/wBA1ZCil5D7SrWqllrSpYvNIrlLqTHF6ixu6oKilmH8Xv4HgdNB2pfmh9k2w5OxFSNvD96uarZ0JOF13QH/UCmr1shDk8QNWS7IlNqrH8/u0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=jjFb/T/9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="jjFb/T/9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3CA31F000E9; Sun, 28 Jun 2026 06:55:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1782629713; bh=sHbfVijReW7xHmccVvO9CNsf1KBaIlaAL2mdy+NudTo=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=jjFb/T/9WdwCYb7F6Yh7CUpxOCstY/0t304rxgf4JCp27/uA+vvISo45pIocdabWD 8mgCVrhhq2o+Rdc67Dz59ySst9iWpL0vnKVKitbWRL0S8aY1hjWoRruZ0Wv8FG1OGr 59l7p7TryXJJWvcVwZyfDH5mHRt5TXomgeJGuB+8= Date: Sat, 27 Jun 2026 23:55:12 -0700 From: Andrew Morton To: Oscar Salvador Cc: Dave Hansen , Karsten Desler , Muchun Song , David Hildenbrand , Lorenzo Stoakes , Vlastimil Babka , "Liam R . Howlett" , Andreas Larsson , "David S . Miller" , Huacai Chen , Alexander Gordeev , Gerald Schaefer , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/8] Stop special-casing hugetlb mappings in get_unmapped_area Message-Id: <20260627235512.787d09b15b3d2ff9441e604a@linux-foundation.org> In-Reply-To: <20260606035003.529685-1-osalvador@suse.de> References: <20260606035003.529685-1-osalvador@suse.de> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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 Sat, 6 Jun 2026 05:49:55 +0200 Oscar Salvador wrote: > A regression was reported on AMD 15h Family for hugetlb mappings when 'align_va_addr' > is set [1]. It would be helpful to say right here that this regression results in a runtime BUG(). Helps get attention ;) > Historically, for hugetlb mappings we always ignored 'align_offset' in get_unmapped_area > functions, but after commit 7bd3f1e1a9ae ("mm: make hugetlb mappings go through > mm_get_unmapped_area_vmflags") that was no longer the case for x86. > > While we could fix that by work it around in x86 code, the truth is that the current > functioning of hugetlb mappings with get_unmapped_area functions is a bit clumsy, and > we can do better. > This patchset aims at two things: > > 1) Fix regression reported in [1] > 2) Stop special-casing hugetlb mappings in get_unmapped_area functions OK, so the offending commit was about 1.5 years ago. Do we want to fix -stable kernels? If so, can we start out with something minimal for backporting? And narrow down its Fixes:? The series was sent at an awkward time in the -rc cycle, which perhaps explains the lack of feedback. I suggest a refresh/retest/resend to help bring people up to speed. Sashiko has quite a lot to say - I hope some of it is useful? https://sashiko.dev/#/patchset/20260606035003.529685-1-osalvador@suse.de