From: Mike Kravetz <mike.kravetz@oracle.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>, Vlastimil Babka <vbabka@suse.cz>,
David Hildenbrand <david@redhat.com>,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 10/10] mm, treewide: Redefine MAX_ORDER sanely
Date: Thu, 16 Mar 2023 16:00:03 -0700 [thread overview]
Message-ID: <20230316230003.GB6211@monkey> (raw)
In-Reply-To: <20230316181547.GA6211@monkey>
On 03/16/23 11:15, Mike Kravetz wrote:
> On 03/15/23 14:31, 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.
> >
> > Change the definition of MAX_ORDER to be inclusive: the range of orders
> > user can ask from buddy allocator is 0..MAX_ORDER now.
> >
> > --- a/arch/arc/Kconfig
> > +++ b/arch/arc/Kconfig
> > @@ -556,7 +556,7 @@ endmenu # "ARC Architecture Configuration"
> >
> > config ARCH_FORCE_MAX_ORDER
> > int "Maximum zone order"
> > - default "12" if ARC_HUGEPAGE_16M
> > - default "11"
> > + default "11" if ARC_HUGEPAGE_16M
> > + default "10"
>
> Is this Kconfig file wrong (off by 1) today? It seems like it wants MAX_ORDER
> to be sufficiently large to allocate 16M if ARC_HUGEPAGE_16M. So, seems like
> it should be 13 today?
Nevermind, PAGE_SIZE seems to be 8K by default although it appears to be
configurable. Not exactly sure how the hard coded values above work if
PAGE_SIZE is configurable. Too confusing for me to make an intelligent
comment. Sorry for the noise.
--
Mike Kravetz
next prev parent reply other threads:[~2023-03-16 23:00 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 [this message]
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
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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