From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fhigh-a1-smtp.messagingengine.com (fhigh-a1-smtp.messagingengine.com [103.168.172.152]) (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 74C3B3B0583 for ; Tue, 6 Oct 2026 09:13:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.152 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791278032; cv=none; b=VhN4v2ahCiMPdIwS2zVovv8Fy06lG2cuu7oL0UqS+2OB8IfIcoWT8PC0s9pUM+ZoHICoFFA+QXrx5UhcM4fOhSem58lvnEqiyIiHXgdn25STH0aM2qbZhe8vENSOrv4Uuyikk1EIQSkbu6sfcnsgbO1/M4sTw384i2Ju4ovcHUA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791278032; c=relaxed/simple; bh=Uzht/gnnalOdKMOxMXIuqX3WZTTWDv2ShAnEFEPyhKE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UdDnKDJGQ6tCRIC1t2sCKA8MfzPrgAL35HQoFZp3MfUbOUOzXhUWYVIVoYU0PopfNYDfjd+QVrqA9wwEnCjUyEj6fvc0AKh95vCkfHTv/H1rGb22Wq4GJ0k2YGYKzv/r/uO+3I5HzFhE2pXTV8Vojj4smFEKQnV7YwasB6cxaEY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name; spf=pass smtp.mailfrom=shutemov.name; dkim=pass (2048-bit key) header.d=shutemov.name header.i=@shutemov.name header.b=MYzNnMS7; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=e0MmQS2y; arc=none smtp.client-ip=103.168.172.152 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shutemov.name Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=shutemov.name header.i=@shutemov.name header.b="MYzNnMS7"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="e0MmQS2y" Received: from phl-compute-03.internal (phl-compute-03.internal [10.202.2.43]) by mailfhigh.phl.internal (Postfix) with ESMTP id 7FC7414000F8 for ; Tue, 6 Oct 2026 05:13:49 -0400 (EDT) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-03.internal (MEProxy); Tue, 06 Oct 2026 05:13:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov.name; h=cc:cc:content-type:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to; s=fm3; t=1791278028; x= 1791364428; bh=MbQD73+crd7vZ9QKN8oet3vSF/p7ePpJtz6mLHHA2fo=; b=M YzNnMS7ZN3wVSn2vEjszZQBWv/gqXaybvo1BuDsA24Dv1uYKul3eMDqRHrZ59TYg NtM50AO+2d+0tzTVAU8OZGJhydpPVoNghkJc6ctrvMtP9EcrTenBLFhsNRfnOg67 RqkkUsqnJdYW8sHuIzL7LEnGDIoc2B1w6eHmwBTOuGI8Yrtx+KV8Ft3Inr3t2qFa cmQ0UPhjVoM9AtN09FGMYD/bskoWSGztPDBUg7ez1AI6PJ+n+vgaUitsJZ20jDnw Pe/caucJEeirWsGMsWpFyxJ8Pqluw2Sfqcnri6h6Ub3W+QEklscvlFznQdE+6CNJ vu9LN2nfJAerHb7zCSJSw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t= 1791278028; x=1791364428; bh=MbQD73+crd7vZ9QKN8oet3vSF/p7ePpJtz6 mLHHA2fo=; b=e0MmQS2yZZ9YatnShEldHczseY8u/Cl142cD7PJEap/5ee30t18 cCTSQo64oi7NTKBxMWcwM/uwx6zKhYqpjpRQCbL+DS9qTZO8p++CpZm3pFdqy7z1 m7kGmofudCFATpHNN69DDVYLq0DwBrc+S/Ie7OEPnHE8/LVSZEeFOcmcRUrHyU4V Ql2v7l4P5Xr/uAZoJizz0kUFpRNcHPnTQcb36QMhJJDFRnBKolVvdqNbUkQJ5oJF 6oCn7XckLLuZovW8XclyLNFekxUGgiKqvb75kr1iavPEcP+HZAHk11IKxIALmO+L 1cPbtmpZr+zsoHTgt6n1yYYbteAZ1PWanrw== X-DKIM2-Info: draft=ietf-dkim-dkim2-spec-06; repo=github.com/dkim2wg/interop; date=2026-10-04; sw=lmtpprox; action=sign d=shutemov.name a=rsa-sha256; DKIM2-Signature: i=1; m=1; t=1791278028; d=shutemov.name; mf=PGtpcmlsbEBzaHV0ZW1vdi5uYW1lPg==; rt=PGxpbnV4LWtlcm5lbEB2Z2VyLmtlcm5lbC5vcmc+; s=fm3:rsa-sha256:MoNRkOUEm5Xv2Tvqm+OlYRQd1O3MaDYonv69QMiiYjyiQcv hUh+StAj5cLPo0XNyNm5ZreYJcJS2ejeSaBDqTfbTZSZwAcY9VqQwOW98zSqNloK wbmBW3cbqXkjPjhrDiUpZvNOP1ATqxnhhSvpRmEGSoTn4SHfUA35Zti1YS8sLl6O fk/oNYrbKm7UG7UYWYtiqyM70DVGJGGET6tmvSUZs2+0Nd7ParA2/P9vRJ5FMjCM zl+VpXDY/qXQAT8RATPfIXF9yaInpnkXPqwCCdlbXxehBQIKno4iIVy3XQKqJJm7 MjcgUu4kXHBYwOPzUmJzEk/da9zF3w9Jt09i/JA==; X-DKIM2-Info: draft=ietf-dkim-dkim2-spec-06; repo=github.com/dkim2wg/interop; date=2026-10-04; sw=lmtpprox; action=mi-m=1; hc=12; hn=cc,content-disposition,content-type,date,feedback-id,from, in-reply-to,message-id,mime-version,references,subject,to; Message-Instance: m=1; h=sha256:3q1TEc8G3uI4UoP5ag6eEF2ixUYiG8Gk1JdkBHKwrdA=:Uzht/gnnalOdKMOxMXIuqX3WZTTWDv2ShAnEFEPyhKE=; X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTGj5C67xIbzcGLTgoQok/07Sc/orEjUInqIagiNX5tzfNrUnfY1jc1lLJwh2gzo3d GB698lLckGkQyvrNDBFvobDZ3AKW7HlEJvdeuEuAlIxo1NdMYrrrtakWUQIQiEjBN1B6ri wKi6qEUiJkKlNVegjOAgd0kUGjoPwR2IgA2mVnAWW8VbDla5+6eFmaorfJUN0WOYRndIYz ROX+4JJqCmnVpPn32jhHBxpZJszOIgw5BxKJ/vniHlQHUTPspDkZn8zhQw0awtlwixI2g3 ZQGvwVpHDDhkkyRNR5r0tSVt1oN1XUrc8PaZB0foWj2F5PK6JJDPxdNR/3G99Mnb2qvrMU c56mQJWj6ObswPBB90YvyTCtHf3ox7HVMuKz78cItUQKSFqXMvsOUzU1YutPwP6Vp0EtNg zvaHKJI42l7V9TJ0PtV+gPEm3VW6l5/XgGbg2LEQIqoNJRWGFRPjO6mVeUFvHnf0OZ+Y/f 4U0nHEL2QJASnnhk7mRiDdptzT/IKVcoui7jBiKWondtSYcFEB2DTr9KCNiVa0Et8B7VNL CCwc12rO2qO9rgrLt9TDix40u9rQecSgc6cc+ZDifD2hr4+OZ8aP4oavNuhISU7/obNUNe ypS3e2WxOARZDzI/ev8A/xhnLBLFoVPsYk/rnhA+zd8K2PQGzyCNC4G75z+A X-ME-Proxy: Feedback-ID: ie3994620:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 6 Oct 2026 05:13:47 -0400 (EDT) Date: Tue, 6 Oct 2026 10:13:46 +0100 From: Kiryl Shutsemau To: Johannes Weiner Cc: Harry Yoo , Vlastimil Babka , Andrew Morton , David Hildenbrand , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Zi Yan , Shakeel Butt , Usama Arif , 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: References: <20260929174553.175333-1-kirill@shutemov.name> <20261006081050.GA234057@cmpxchg.org> 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-Disposition: inline In-Reply-To: <20261006081050.GA234057@cmpxchg.org> On Tue, Oct 06, 2026 at 10:10:50AM +0200, Johannes Weiner wrote: > Without counter indication, I would prefer to keep the tighter > guarantees. ISTR this mattered on some of my ext4 tests in the past > with the buffer locking. OK, v2 takes the priority floor and the COMPACT_SUCCESS retry limit from the requested order, with the explicit promoted order folded in. > > Should defrag_mode treat MIGRATE_MOVABLE like ZONE_MOVABLE there and > > move the page out at pin time? Ideally we might want to move it back > > on unpin, but it can be done by compaction too. > > Should it even be specific to defrag_mode? I suppose without it, the > poisoning from fallbacks would dominate by a landslide under > pressure. But these pins can mess with compactability long before > becoming capacity-bound. Agreed, a pinned page in a movable block hurts compaction regardless of defrag_mode. It can make longterm pinning more expensive, but it is the right place to pay the cost. -- Kiryl Shutsemau / Kirill A. Shutemov