From: David Laight <David.Laight@ACULAB.COM>
To: 'Mel Gorman' <mgorman@suse.de>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
David Hildenbrand <david@redhat.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 00/10] Fix confusion around MAX_ORDER
Date: Thu, 23 Mar 2023 15:03:56 +0000 [thread overview]
Message-ID: <54496a4d8b31499993aac50f2979f99a@AcuMS.aculab.com> (raw)
In-Reply-To: <20230321163845.qpybxa5rlwclvko2@suse.de>
From: Mel Gorman
> Sent: 21 March 2023 16:39
>
> On Wed, Mar 15, 2023 at 02:31:23PM +0300, Kirill A. Shutemov wrote:
> > MAX_ORDER currently defined as number of orders page allocator supports:
> > user can ask buddy allocator for page order between 0 and MAX_ORDER-1.
> >
> > This definition is counter-intuitive and lead to number of bugs all over
> > the kernel.
> >
> > Fix the bugs and then change the definition of MAX_ORDER to be
> > inclusive: the range of orders user can ask from buddy allocator is
> > 0..MAX_ORDER now.
> >
>
> Acked-by: Mel Gorman <mgorman@suse.de>
>
> Overall looks sane other than the fixups that need to be added as
> flagged by LKP. There is a mild risk for stable backports that reference
> MAX_ORDER but that's the responsibilty of who is doing the backport.
> There is a mild risk of muscle memory adding off-by-one errors for new
> code using MAX_ORDER but it's low.
How many of the places that use MAX_ORDER weren't touched?
Is it actually worth changing the name at the same time.
That will stop stable backport issues.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2023-03-23 15:06 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-15 11:31 [PATCH 00/10] Fix confusion around MAX_ORDER Kirill A. Shutemov
2023-03-15 11:31 ` [PATCH 01/10] sparc/mm: Fix MAX_ORDER usage in tsb_grow() Kirill A. Shutemov
2023-03-16 3:04 ` Mike Kravetz
2023-03-17 8:46 ` Mike Rapoport
2023-03-17 8:35 ` Mike Rapoport
2023-03-21 7:48 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 02/10] um: Fix MAX_ORDER usage in linux_main() Kirill A. Shutemov
2023-03-17 8:49 ` Mike Rapoport
2023-03-21 7:49 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 03/10] floppy: Fix MAX_ORDER usage Kirill A. Shutemov
2023-03-17 8:53 ` Mike Rapoport
2023-03-21 7:53 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 04/10] drm/i915: Fix MAX_ORDER usage in i915_gem_object_get_pages_internal() Kirill A. Shutemov
2023-03-15 14:18 ` Tvrtko Ursulin
2023-03-15 15:28 ` Kirill A. Shutemov
2023-03-15 15:35 ` Tvrtko Ursulin
2023-03-15 15:38 ` Kirill A. Shutemov
2023-03-16 8:55 ` Tvrtko Ursulin
2023-03-21 7:57 ` Vlastimil Babka
2023-03-21 7:55 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 05/10] genwqe: Fix MAX_ORDER usage Kirill A. Shutemov
2023-03-21 7:59 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 06/10] perf/core: Fix MAX_ORDER usage in rb_alloc_aux_page() Kirill A. Shutemov
2023-03-21 8:00 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 07/10] mm/page_reporting: Fix MAX_ORDER usage in page_reporting_register() Kirill A. Shutemov
2023-03-21 8:01 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 08/10] mm/slub: Fix MAX_ORDER usage in calculate_order() Kirill A. Shutemov
2023-03-16 11:18 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 09/10] iommu: Fix MAX_ORDER usage in __iommu_dma_alloc_pages() Kirill A. Shutemov
2023-03-15 12:18 ` Robin Murphy
2023-03-22 12:20 ` Joerg Roedel
2023-03-15 16:07 ` Jacob Pan
2023-03-21 8:05 ` Vlastimil Babka
2023-03-15 11:31 ` [PATCH 10/10] mm, treewide: Redefine MAX_ORDER sanely Kirill A. Shutemov
2023-03-15 15:06 ` kernel test robot
2023-03-15 15:26 ` Kirill A. Shutemov
2023-03-15 15:26 ` kernel test robot
2023-03-15 15:38 ` Kirill A. Shutemov
2023-03-16 17:09 ` Zi Yan
2023-03-16 23:21 ` Kirill A. Shutemov
2023-03-17 13:17 ` Zi Yan
2023-03-16 18:15 ` Mike Kravetz
2023-03-16 23:00 ` Mike Kravetz
2023-03-16 23:30 ` Kirill A. Shutemov
2023-03-17 1:57 ` Vineet Gupta
2023-03-21 11:22 ` Vlastimil Babka
2023-03-22 3:26 ` Michael Ellerman
2023-03-21 16:38 ` [PATCH 00/10] Fix confusion around MAX_ORDER Mel Gorman
2023-03-23 15:03 ` David Laight [this message]
2023-09-27 17:11 ` Paolo Bonzini
2023-09-28 7:50 ` Mikulas Patocka
2023-09-28 16:57 ` Paolo Bonzini
2023-10-17 10:46 ` Pavel Machek
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