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Mon, 27 Jul 2026 09:50:18 -0700 (PDT) Date: Mon, 27 Jul 2026 12:50:17 -0400 From: Johannes Weiner To: Brendan Jackman Cc: Andrew Morton , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Zi Yan , David Hildenbrand , Lorenzo Stoakes , "Liam R . Howlett" , Mike Rapoport , Shakeel Butt , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2 4/4] mm: page_alloc: fix non-movable reclaim storm in defrag_mode Message-ID: References: <20260722150006.3848560-1-hannes@cmpxchg.org> <20260722150006.3848560-5-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 68610A0009 X-Stat-Signature: q8upwzscxrnbh9qcdxisirdbjrg7pu3a X-HE-Tag: 1785171020-13945 X-HE-Meta: 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 E39LiUtR fmKrcWN69lEs3Ku9NSEX/61IUz4WzkVm+cCdWEfkLfDWmUpi/ET4C0GELirzWse1LypyvC5P3AfbIYvjllC+bEe+GUiyx1gF0ZYfjx0R4JLVgWCii50Mlu+o39JRPV6VuRm2gm2/uqA1NabHjo67nPojMAhUpS6HV8h82XiONnwi8vJusbKyuatoFZ9CM1I73ZPvryrHrxVqLcjSrEelfd+v0JIj2Y/DWJ3SlPfkIGXgpDboJd06XG6K66FOWR38Iohlxk84J0XElpdKokFDHwmwhcVxc2GFogYF6tNyMwWdkcGLU/L/imkSpMIDNVuJMnB+AZsq3HDSyIwENaA9Nd3YCEsiHu9hI4/WvzEosV3DOVTORMMk7bjd8s+CTvF8NK+I+iSR2cNjeYDRFmLPSsWrDqupCOEVedv1hHiPu7pKhTs0FHrZz2/xlFw6Y3R04tyMftOPQ/723AsI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, Jul 25, 2026 at 12:34:29PM +0000, Brendan Jackman wrote: > On Wed Jul 22, 2026 at 2:56 PM UTC, Johannes Weiner wrote: > > @@ -4169,8 +4185,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, > > barrier(); > > WRITE_ONCE(current->capture_control, &capc); > > > > - *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, > > - prio, &capc); > > + *compact_result = try_to_compact_pages(gfp_mask, compact_order, > > + alloc_flags, ac, prio, &capc); > > > > Nit: the comment for try_to_compact_pages() is falsified by this, > we need something like: Yes, good catch. Thanks. Andrew, would you mind folding this difflet in place? > diff --git i/mm/compaction.c w/mm/compaction.c > index 0568623d9384d..ca57403dc1522 100644 > --- i/mm/compaction.c > +++ w/mm/compaction.c > @@ -2823,7 +2823,7 @@ static enum compact_result compact_zone_order(struct zone *zone, int order, > /** > * try_to_compact_pages - Direct compact to satisfy a high-order allocation > * @gfp_mask: The GFP mask of the current allocation > - * @order: The order of the current allocation > + * @order: The order to try and make available > * @alloc_flags: The allocation flags of the current allocation > * @ac: The context of current allocation > * @prio: Determines how hard direct compaction should try to succeed