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 08D923A2E36 for ; Wed, 1 Jul 2026 13:45:06 +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=1782913508; cv=none; b=evWXzrqi8oMtxiIa2YRkL09zKL+XZNm+5hvfeMN2NSOa9D+bLrVcszODGnx1zabkREejv9shL2qRckn+CjVWtmbiB3fTZREfVP1w0gVwRPQqfMxh52rrqezeb+TEpmOx8TC924x1saEmR4+huZRRGJh2mn0rkyqIW0AbuUQFrKA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782913508; c=relaxed/simple; bh=lgS0w6pURUmSlfJP06buFvNGuKPG3yulwvtwXZAn28k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=izei0QlbEbv4VERNKvNaf9UOA+LTEXKSdh+TnPjuOs1gG2DDhuJtpD4OpiRaCfX+P/jpKg8u6r6z2jlQf328iSCA74yOd9jj68TKE3MyWeHY1koo9Fh6XPyg/CjidgYE8zinLP5jtZzhh6aqGbMuODvN6ZNUz8XNkWu3uLbaduw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BuJ9TuFR; 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="BuJ9TuFR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6847D1F000E9; Wed, 1 Jul 2026 13:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782913506; bh=5HIMt8vd/cSScdTbWcHyMdsr8orHlxMIASQqoZMTnhY=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=BuJ9TuFROTgJKp0cHyweUaF/pssBDFAWlmUCBn+T5GRqW96S8jUzGmJ/yOyjZcLAC Z2jOmAl//qkcaIsojP7ECRoMHSIOaloSBEscEwzPyrxgWephEYnTSbQ+wDA3kVhwcY 3Z/BBtTPgM9GtqTUw57m3I3o57rQsHnXuzduMfQp6JtrlI58/41OPPluj9rAUDT1eN f4kFuKzZ7/Gf72HajoqaadIsCCt856ZU04gUoYXr63HU022dDytHddW/5AyUxsiyW+ U+ma1UyPi98+BVzHTZ11mIea6gjTRZMZ5Yvltsc3Nt2+27lZKyOagxqg8R72GalXKy zOwNWoNegLf+w== Message-ID: <5efb2e20-e4fc-4e04-a771-532cb393e46a@kernel.org> Date: Wed, 1 Jul 2026 15:45:02 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/4] mm: page_alloc: __GFP_FS lockdep annotation for direct compaction Content-Language: en-US To: Johannes Weiner , Andrew Morton Cc: Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Zi Yan , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260626182215.1107966-1-hannes@cmpxchg.org> <20260626182215.1107966-2-hannes@cmpxchg.org> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: <20260626182215.1107966-2-hannes@cmpxchg.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/26/26 20:21, Johannes Weiner wrote: > A subsequent patch will have some order-0 allocations participate in > compaction under defrag_mode, to stave off extfrag events. > > Since this is a sprawling expansion of entry points, and compaction > can enter filesystem paths, add lockdep annotations that catches > __GFP_FS passing errors. > > Direct reclaim has had this annotation for a while, and since reclaim > and compaction are usually used in conjunction, this is unlikely to > unearth old bugs. It's more about future proofing and peace of mind. > > Signed-off-by: Johannes Weiner Reviewed-by: Vlastimil Babka (SUSE) > --- > mm/page_alloc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index ee902a468c2f..cb422505c6ef 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4152,12 +4152,14 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, > > psi_memstall_enter(&pflags); > delayacct_compact_start(); > + fs_reclaim_acquire(gfp_mask); > noreclaim_flag = memalloc_noreclaim_save(); > > *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, > prio, &page); > > memalloc_noreclaim_restore(noreclaim_flag); > + fs_reclaim_release(gfp_mask); > psi_memstall_leave(&pflags); > delayacct_compact_end(); >