From: Andrew Morton <akpm@linux-foundation.org>
To: Hillf Danton <dhillf@gmail.com>
Cc: Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.cz>,
Michel Lespinasse <walken@google.com>
Subject: Re: [PATCH resend] rmap: recompute pgoff for unmapping huge page
Date: Wed, 6 Mar 2013 14:20:11 -0800 [thread overview]
Message-ID: <20130306142011.c6260e416cef6a906660fa4d@linux-foundation.org> (raw)
In-Reply-To: <CAJd=RBD0UWxpMv7W78fH0U_zBAOozP1owaMePGaUEVitotRfBg@mail.gmail.com>
On Mon, 4 Mar 2013 20:47:31 +0800 Hillf Danton <dhillf@gmail.com> wrote:
> [Resend due to error in delivering to linux-kernel@vger.kernel.org,
> caused probably by the rich format provided by the mail agent by default.]
>
> We have to recompute pgoff if the given page is huge, since result based on
> HPAGE_SIZE is not approapriate for scanning the vma interval tree, as shown
> by commit 36e4f20af833(hugetlb: do not use vma_hugecache_offset() for
> vma_prio_tree_foreach)
>
> Signed-off-by: Hillf Danton <dhillf@gmail.com>
> ---
>
> --- a/mm/rmap.c Mon Mar 4 20:00:00 2013
> +++ b/mm/rmap.c Mon Mar 4 20:02:16 2013
> @@ -1513,6 +1513,9 @@ static int try_to_unmap_file(struct page
> unsigned long max_nl_size = 0;
> unsigned int mapcount;
>
> + if (PageHuge(page))
> + pgoff = page->index << compound_order(page);
> +
> mutex_lock(&mapping->i_mmap_mutex);
> vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
> unsigned long address = vma_address(page, vma);
How are we getting here for hugepages? Trying to migrate a hugetlbfs
page?
Can we just do this?
--- a/mm/rmap.c~a
+++ a/mm/rmap.c
@@ -1505,7 +1505,7 @@ static int try_to_unmap_anon(struct page
static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
{
struct address_space *mapping = page->mapping;
- pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ pgoff_t pgoff;
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
unsigned long cursor;
@@ -1513,6 +1513,7 @@ static int try_to_unmap_file(struct page
unsigned long max_nl_size = 0;
unsigned int mapcount;
+ pgoff = page->index << compound_order(page);
mutex_lock(&mapping->i_mmap_mutex);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);
_
It's a lot less fuss.
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next prev parent reply other threads:[~2013-03-06 22:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-04 12:47 Hillf Danton
2013-03-06 22:20 ` Andrew Morton [this message]
2013-03-06 22:22 ` Andrew Morton
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