From: Roman Gushchin <roman.gushchin@linux.dev>
To: David Hildenbrand <david@redhat.com>
Cc: Frank van der Linden <fvdl@google.com>,
linux-mm@kvack.org, muchun.song@linux.dev,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] mm/hugetlb: pass correct order_per_bit to cma_declare_contiguous_nid
Date: Thu, 4 Apr 2024 13:52:55 -0700 [thread overview]
Message-ID: <Zg8TJ3CERBAdJRTd@P9FQF9L96D.corp.robot.car> (raw)
In-Reply-To: <e74cfee3-565f-4c69-bb7b-bdd40d01d212@redhat.com>
On Thu, Apr 04, 2024 at 10:13:21PM +0200, David Hildenbrand wrote:
> On 04.04.24 18:25, Frank van der Linden wrote:
> > The hugetlb_cma code passes 0 in the order_per_bit argument to
> > cma_declare_contiguous_nid (the alignment, computed using the
> > page order, is correctly passed in).
> >
> > This causes a bit in the cma allocation bitmap to always represent
> > a 4k page, making the bitmaps potentially very large, and slower.
> >
> > So, correctly pass in the order instead.
> >
> > Signed-off-by: Frank van der Linden <fvdl@google.com>
> > Cc: Roman Gushchin <roman.gushchin@linux.dev>
> > Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
>
> It might be subopimal, but do we call it a "BUG" that needs "fixing". I
> know, controversial :)
We probably should not rush with a stable backporting, especially given your
next comment on page sizes on arm.
next prev parent reply other threads:[~2024-04-04 20:53 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-04 16:25 [PATCH 1/2] mm/cma: drop incorrect alignment check in cma_init_reserved_mem Frank van der Linden
2024-04-04 16:25 ` [PATCH 2/2] mm/hugetlb: pass correct order_per_bit to cma_declare_contiguous_nid Frank van der Linden
2024-04-04 18:56 ` Roman Gushchin
2024-04-04 19:40 ` Frank van der Linden
2024-04-04 20:45 ` Roman Gushchin
2024-04-04 20:13 ` David Hildenbrand
2024-04-04 20:52 ` Roman Gushchin [this message]
2024-04-04 22:02 ` Frank van der Linden
2024-04-04 22:20 ` Andrew Morton
2024-04-04 21:44 ` Frank van der Linden
2024-04-04 22:22 ` Frank van der Linden
2024-04-08 8:15 ` David Hildenbrand
2024-04-04 20:17 ` Andrew Morton
2024-04-04 21:58 ` Frank van der Linden
2024-04-07 8:02 ` Muchun Song
2024-04-04 20:15 ` [PATCH 1/2] mm/cma: drop incorrect alignment check in cma_init_reserved_mem Andrew Morton
2024-04-04 20:45 ` Frank van der Linden
[not found] ` <93eccef7-a559-4ad8-be0f-8cc99c00bd09@redhat.com>
2024-04-04 20:48 ` Frank van der Linden
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