From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.20 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793955543; b=xFWOH2zqBsRkjCGWgM94MOg890i/V2wIC79PRYVnWG52DmK1JXQEnOPPsQnVuX6NT2IO 5UyDm24k5eGvzcDCPcPICEeJGtKq3pFaeEFXvBIFRzXjp+NxxkQihe9O3zOx6GFh4t1sa jrRAatBVDlEZZQcEYW/Q80xENh41dTJV5NsKLdR/0GLQ0JdV5ER3Wt+ItpZErnWBpCLEi duPSq6WMaTHP/lUFgkjg3UbHdw2UXQR/AFseHakNaIqimfyW4MBgm0xXzcdbtH6Nzt+xj tlMfZLkbTLdboDRKLumeQIoGF80yrajtEMJPBmfrlUk69A1E0211FNSLwzsayZOw2sQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793955543; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=Yh+ePy4k2Ej6351I944wQj3itVcd2iIkRAI/E3uzaMY=; b=Uugs1dQcb++zll9vEIJaKK2IjGKxy38F/GwV2lzfn0t+ZUEi8iuuDK1aAAq0JyKTWC6C QgEG6Oa8KcWnsZi2TU+060m512ioC9lWyseuaNXWeqoHIi5SVOCbbV1WbRLzqoxYZtm8t YCTFh28vbHOPlHNOml7OfWi0c/jbK8cVYZ9QVAd76hvvhsGv0QPQcLaA/zUmjMllA0wzq nJYdtaeluakQlFnl0MRGNWQDTWMxyjut06M454/jI8epS2627oK32OjoMon+yAXV6BO+U tV8bWIcOtg5NgjBzDcgY4qMTOjhix6aA/9yOltntdLvjzi7vBmF1qsF4QXQCxUSNTQA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=bQggY6Sf; arc=none smtp.remote-ip=95.215.58.20 Received: from mta1.migadu.com (out-20.mta1.migadu.com [95.215.58.20]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BC36606A32C for ; Fri, 6 Nov 2026 08:59:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 5BC36606A32C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=bQggY6Sf X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=ragY6FzqrbiIYwHJcjk3800TKOnL9b0LX6exoGgGvrI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793955540; v=1; x=1794560340; b=bQggY6SfCbxRY2UHK2EIOX4BV1trzD6hlgH6mA9zcyurzJ9/BA4o5GjbMHM5adXG6nIV92m6 cMpxhlILSSBPmZnBzNWQYjYznBzO43Uwvukss0Pt0BJJekCqsBaguJ+TuO8AxP9uwGmW241x297 ZyB076wfrRFg45F4MemmEz78= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id b07fd71a6e5f18a4; Fri, 06 Nov 2026 08:59:00 +0000 X-Mizu-Trace-ID: b07fd71a6e5f18a4 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.200.71.1.16\)) Subject: Re: [PATCH v3 04/12] mm: hugetlb_vmemmap: generalize vmemmap page allocation From: Muchun Song In-Reply-To: <20261104023510.260766-5-songmuchun@bytedance.com> Date: Fri, 6 Nov 2026 16:58:46 +0800 Cc: Oscar Salvador , Andrew Morton , Mike Rapoport , Qi Zheng , Lance Yang , James Houghton , David Hildenbrand , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: <08143A6C-D96D-4E6B-B7F3-359E9311B272@linux.dev> References: <20261104023510.260766-1-songmuchun@bytedance.com> <20261104023510.260766-5-songmuchun@bytedance.com> To: Muchun Song X-Mailer: Apple Mail (2.3901.200.71.1.16) > On Nov 4, 2026, at 10:35, Muchun Song wrote: > > Vmemmap page allocation is currently tied to restoring a virtual range > and assumes an empty destination list. These constraints prevent it from > being reused when pages are requested independently of a vmemmap range or > appended to an existing list. > > Generalize the allocator and give it an all-or-nothing list contract so > the restore and optimization paths can share the same allocation policy. > This also allows HVO head-page allocation to fail gracefully under memory > pressure without triggering the OOM killer. Before this report [1], I did not realize that this unexpected behavior change fixed a real issue. Therefore, in the next version update, I will extract the GFP_KERNEL modification from this patch as a prerequisite patch and place it at the very front of this series to fix this issue, so as to facilitate backporting. [1] https://lore.kernel.org/all/20261104133938.50974-1-zhangyili01@baidu.com/ Thanks, Muchun