proc: optimise smaps for shmem entries

Avoid bumping the refcount on pages when we're only interested in the
swap entries.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: https://lkml.kernel.org/r/20200910183318.20139-5-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-10-13 16:51:28 -07:00 committed by Linus Torvalds
parent e6e88712e4
commit 8cf886463e

View File

@ -520,16 +520,10 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
page = device_private_entry_to_page(swpent);
} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
&& pte_none(*pte))) {
page = find_get_entry(vma->vm_file->f_mapping,
page = xa_load(&vma->vm_file->f_mapping->i_pages,
linear_page_index(vma, addr));
if (!page)
return;
if (xa_is_value(page))
mss->swap += PAGE_SIZE;
else
put_page(page);
return;
}