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 5296836E467; Wed, 30 Sep 2026 20:03:00 +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=1790798582; cv=none; b=R1Xqm2dISyawyvYafljHlODkGnJUdKkM92W4YgUf0x1oip1bymgGlQeINoHxauuERcblpW4sWY8xoRuUUgHIwiOU0gY1E8VoM5abmr3s3oof/gaQpyy4quwGs0tEyhvq9HUAfUjo2YDGoBK/I7wXUaAwr0JWzkbtjczNGKOIwew= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790798582; c=relaxed/simple; bh=wdmewPuK0kw+vIRfKmx97qxuPpuP2nxQdBydnafiVTU=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=BtQfY+ZDHj6hmr7T7zQqXA9lRgyjiZspblhbiqOsqbjwp5UOhwq//Rl0KDx2aMxaF08H5+P51TYnkev3bq0wOi6CW4XAcu8lvVcfLgmypasd3VZkRFVn6bEPclACjixfly5+AADpWK4kqHJFoRCgRWGmsudL4+4yXbfJVls3cIc= 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=ExlvIxdb; 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="ExlvIxdb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B1381F000FF; Wed, 30 Sep 2026 20:03:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790798580; bh=u08t18FaZZ/JoItkaTytwkoDNv5W489UK9Ej3SaW7sM=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ExlvIxdbN8JjqNmq7VsmSrsVUc6pxFiLPpW5EV0yT5cQhwrumhMEM2DrYiSKwxFRB V0Ji2JQN3kuDi4RDUu8ZXgrmY/sbD74AO6RjhEG3qSGzjUDpJ5VTWQMmcxmI6c07ZZ uQFr429+DI/V4CQzuFxFOwzlTC6jfTnwaB51VOlE= Date: Wed, 30 Sep 2026 13:02:59 -0700 From: Andrew Morton To: Kiryl Shutsemau Cc: Vlastimil Babka , Johannes Weiner , David Hildenbrand , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Zi Yan , Shakeel Butt , Usama Arif , Harry Yoo , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH] mm: page_alloc: make defrag_mode retries follow the promoted order Message-Id: <20260930130259.8d7d967f4a38afa34e051145@linux-foundation.org> In-Reply-To: References: <20260929174553.175333-1-kirill@shutemov.name> <20260929125816.5a846a62943eeaf63725b525@linux-foundation.org> 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 Wed, 30 Sep 2026 13:35:01 +0100 Kiryl Shutsemau wrote: > On Tue, Sep 29, 2026 at 12:58:16PM -0700, Andrew Morton wrote: > > On Tue, 29 Sep 2026 18:45:51 +0100 Kiryl Shutsemau wrote: > > > > > From: "Kiryl Shutsemau (Meta)" > > > > > > Since commit 7e8756d7ad22 ("mm: page_alloc: fix non-movable reclaim > > > storm in defrag_mode"), direct reclaim and compaction for non-movable > > > requests under defrag_mode run at pageblock_order, to produce the whole > > > blocks that ALLOC_NOFRAGMENT needs. The retry decisions that follow > > > still use the request order. An order-0 request can therefore retry > > > indefinitely without ever reaching the ALLOC_NOFRAGMENT fallback: > > > > 7e8756d7ad22 is new in 7.3-rcX, so no cc:stable needed. > > The commit itself has cc:stable. And it is in 6.18.50 and 7.2.4. > The fix needs to follow it there. doh. > We are running 7.1 with 7e8756d7ad22 backported. We found defrag mode > crucial if we want to use large folios in page cache. > > But nobody besides us seems to test it :/ > > Can we make it default pretty please? :P Send a patch ;)