path: root/mm/swap_state.c
diff options
authorYang Shi <yang.shi@linux.alibaba.com>2019-03-05 15:44:15 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-05 21:07:16 -0800
commite9f598730ea0dde3b45560766240503367c404b7 (patch)
treecd91c28dcbff90c3f8950a7551db34987bcbe5c6 /mm/swap_state.c
parentmm: swap: check if swap backing device is congested or not (diff)
mm: swap: add comment for swap_vma_readahead
swap_vma_readahead()'s comment is missing, just add it. Link: http://lkml.kernel.org/r/1546543673-108536-2-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Hugh Dickins <hughd@google.com Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swap_state.c')
1 files changed, 15 insertions, 1 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 56a3cc4f1068..85245fdec8d9 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -523,7 +523,7 @@ static unsigned long swapin_nr_pages(unsigned long offset)
* This has been extended to use the NUMA policies from the mm triggering
* the readahead.
- * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL.
+ * Caller must hold read mmap_sem if vmf->vma is not NULL.
struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
struct vm_fault *vmf)
@@ -698,6 +698,20 @@ static void swap_ra_info(struct vm_fault *vmf,
+ * swap_vma_readahead - swap in pages in hope we need them soon
+ * @entry: swap entry of this memory
+ * @gfp_mask: memory allocation flags
+ * @vmf: fault information
+ *
+ * Returns the struct page for entry and addr, after queueing swapin.
+ *
+ * Primitive swap readahead code. We simply read in a few pages whoes
+ * virtual addresses are around the fault address in the same vma.
+ *
+ * Caller must hold read mmap_sem if vmf->vma is not NULL.
+ *
+ */
static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
struct vm_fault *vmf)