From: Hugh Dickins <hugh@veritas.com>
tmpfs pages should be surfing the LRUs in the company of their filemap
friends: I was expecting the rules to change, but they've been stable so
long, let's sprinkle mark_page_accessed in the equivalent places here; but
(don't ask me why) SetPageReferenced in shmem_file_write. Ooh, and
shmem_populate was missing a flush_page_to_ram.
mm/shmem.c | 28 +++++++++++++++++++++-------
1 files changed, 21 insertions(+), 7 deletions(-)
diff -puN mm/shmem.c~tmpfs-4-use-mark_page_accessed mm/shmem.c
--- 25/mm/shmem.c~tmpfs-4-use-mark_page_accessed 2003-04-02 22:51:09.000000000 -0800
+++ 25-akpm/mm/shmem.c 2003-04-02 22:51:09.000000000 -0800
@@ -951,6 +951,7 @@ struct page *shmem_nopage(struct vm_area
if (error)
return (error == -ENOMEM)? NOPAGE_OOM: NOPAGE_SIGBUS;
+ mark_page_accessed(page);
flush_page_to_ram(page);
return page;
}
@@ -978,6 +979,8 @@ static int shmem_populate(struct vm_area
if (err)
return err;
if (page) {
+ mark_page_accessed(page);
+ flush_page_to_ram(page);
err = install_page(mm, vma, addr, page, prot);
if (err) {
page_cache_release(page);
@@ -1192,6 +1195,8 @@ shmem_file_write(struct file *file, cons
break;
}
+ if (!PageReferenced(page))
+ SetPageReferenced(page);
set_page_dirty(page);
page_cache_release(page);
@@ -1264,13 +1269,20 @@ static void do_shmem_file_read(struct fi
}
nr -= offset;
- /* If users can be writing to this page using arbitrary
- * virtual addresses, take care about potential aliasing
- * before reading the page on the kernel side.
- */
- if (!list_empty(&mapping->i_mmap_shared) &&
- page != ZERO_PAGE(0))
- flush_dcache_page(page);
+ if (page != ZERO_PAGE(0)) {
+ /*
+ * If users can be writing to this page using arbitrary
+ * virtual addresses, take care about potential aliasing
+ * before reading the page on the kernel side.
+ */
+ if (!list_empty(&mapping->i_mmap_shared))
+ flush_dcache_page(page);
+ /*
+ * Mark the page accessed if we read the beginning.
+ */
+ if (!offset)
+ mark_page_accessed(page);
+ }
/*
* Ok, we have the page, and it's up-to-date, so
@@ -1523,6 +1535,7 @@ static int shmem_readlink(struct dentry
return res;
res = vfs_readlink(dentry, buffer, buflen, kmap(page));
kunmap(page);
+ mark_page_accessed(page);
page_cache_release(page);
return res;
}
@@ -1535,6 +1548,7 @@ static int shmem_follow_link(struct dent
return res;
res = vfs_follow_link(nd, kmap(page));
kunmap(page);
+ mark_page_accessed(page);
page_cache_release(page);
return res;
}
_