From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Andi Kleen <ak@linux.intel.com>, Hugh Dickins <hughd@google.com>,
Hillf Danton <dhillf@gmail.com>,
linux-kernel@vger.kernel.org,
Heiko Carstens <heiko.carstens@de.ibm.com>
Subject: Re: [RFC v2 PATCH 1/7] thp: remove assumptions on pgtable_t type
Date: Fri, 31 Aug 2012 09:10:12 +0200 [thread overview]
Message-ID: <20120831091012.7b710326@de.ibm.com> (raw)
In-Reply-To: <877gsf633x.fsf@linux.vnet.ibm.com>
On Fri, 31 Aug 2012 10:59:38 +0530
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> wrote:
> Gerald Schaefer <gerald.schaefer@de.ibm.com> writes:
>
> > The thp page table pre-allocation code currently assumes that pgtable_t
> > is of type "struct page *". This may not be true for all architectures,
> > so this patch removes that assumption by replacing the functions
> > prepare_pmd_huge_pte() and get_pmd_huge_pte() with two new functions
> > that can be defined architecture-specific.
> >
> > It also removes two VM_BUG_ON checks for page_count() and page_mapcount()
> > operating on a pgtable_t. Apart from the VM_BUG_ON removal, there will
> > be no functional change introduced by this patch.
>
> Why is that VM_BUG_ON not needed any more ? What is that changed which break
> that requirement ?
Because pgtable_t for s390 is not a page and there simply is no page_count or
page_mapcount.
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
next prev parent reply other threads:[~2012-08-31 7:10 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-29 15:32 [RFC v2 PATCH 0/7] thp: transparent hugepages on s390 Gerald Schaefer
2012-08-29 15:32 ` [RFC v2 PATCH 1/7] thp: remove assumptions on pgtable_t type Gerald Schaefer
2012-08-31 5:29 ` Aneesh Kumar K.V
2012-08-31 7:10 ` Martin Schwidefsky [this message]
2012-09-04 22:56 ` Andrea Arcangeli
2012-09-05 17:12 ` Gerald Schaefer
2012-08-29 15:32 ` [RFC v2 PATCH 2/7] thp: introduce pmdp_invalidate() Gerald Schaefer
2012-08-29 15:33 ` [RFC v2 PATCH 3/7] thp: make MADV_HUGEPAGE check for mm->def_flags Gerald Schaefer
2012-08-29 15:33 ` [RFC v2 PATCH 4/7] thp, s390: thp splitting backend for s390 Gerald Schaefer
2012-08-29 15:33 ` [RFC v2 PATCH 5/7] thp, s390: thp pagetable pre-allocation " Gerald Schaefer
2012-08-29 15:33 ` [RFC v2 PATCH 6/7] thp, s390: disable thp for kvm host on s390 Gerald Schaefer
2012-08-29 15:33 ` [RFC v2 PATCH 7/7] thp, s390: architecture backend for thp " Gerald Schaefer
2012-08-30 19:54 ` [RFC v2 PATCH 0/7] thp: transparent hugepages " Andrew Morton
2012-08-31 7:07 ` Martin Schwidefsky
2012-08-31 19:47 ` Andrew Morton
2012-09-04 22:40 ` Andrea Arcangeli
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