linux-kernel - Re: [PATCH v4 4/4] mm/page_isolation: remove migratetype parameter from more functions.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <72e15406-ffd2-4344-8cc6-1d54005138ce@suse.cz>
Date: Sat, 17 May 2025 22:21:46 +0200
From: Vlastimil Babka <vbabka@...e.cz>
To: Zi Yan <ziy@...dia.com>, David Hildenbrand <david@...hat.com>,
 Oscar Salvador <osalvador@...e.de>, Johannes Weiner <hannes@...xchg.org>,
 linux-mm@...ck.org
Cc: Andrew Morton <akpm@...ux-foundation.org>,
 Baolin Wang <baolin.wang@...ux.alibaba.com>,
 "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
 Mel Gorman <mgorman@...hsingularity.net>,
 Suren Baghdasaryan <surenb@...gle.com>, Michal Hocko <mhocko@...e.com>,
 Brendan Jackman <jackmanb@...gle.com>, Richard Chang
 <richardycc@...gle.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 4/4] mm/page_isolation: remove migratetype parameter
 from more functions.

On 5/9/25 22:01, Zi Yan wrote:
> migratetype is no longer overwritten during pageblock isolation,
> start_isolate_page_range(), has_unmovable_pages(), and
> set_migratetype_isolate() no longer need which migratetype to restore
> during isolation failure.
> 
> For has_unmoable_pages(), it needs to know if the isolation is for CMA
> allocation, so adding CMA_ALLOCATION to isolation flags to provide the
> information.
> 
> alloc_contig_range() no longer needs migratetype. Replace it with
> a newly defined acr_flags_t to tell if an allocation is for CMA. So does
> __alloc_contig_migrate_range().
> 
> Signed-off-by: Zi Yan <ziy@...dia.com>

AFAICS has_unmovable_pages() adds the flags parameter but doesn't use it.

But also, I think having both mode and flags is just unnecessary complexity
in this case? CMA_ALLOCATION could be just a new flag? Even if some flag
combinations wouldn't logicaly make sense, this has only so few users so we
don't have to care to make them exclusive with the mode thing.
Also I think REPORT_FAILURE is only used with MEMORY_OFFLINE so it could be
squashed?