[v5,2/2] mm: swap: add comment for swap_vma_readahead
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Message ID 1546543673-108536-2-git-send-email-yang.shi@linux.alibaba.com
State In Next
Commit dffe44d060b8fec075d60af92d8276cbbb6b0a42
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Series
  • [v5,1/2] mm: swap: check if swap backing device is congested or not
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Commit Message

Yang Shi Jan. 3, 2019, 7:27 p.m. UTC
swap_vma_readahead()'s comment is missed, just add it.

Cc: Huang Ying <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
---
v5: Fixed the comments per Ying Huang

 mm/swap_state.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

Comments

Huang, Ying Jan. 4, 2019, 2:25 a.m. UTC | #1
Yang Shi <yang.shi@linux.alibaba.com> writes:

> swap_vma_readahead()'s comment is missed, just add it.
>
> Cc: Huang Ying <ying.huang@intel.com>
> Cc: Tim Chen <tim.c.chen@intel.com>
> Cc: Minchan Kim <minchan@kernel.org>
> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>

Thank!

Reviewed-by: "Huang, Ying" <ying.huang@intel.com>

Best Regards,
Huang, Ying

> ---
> v5: Fixed the comments per Ying Huang
>
>  mm/swap_state.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/mm/swap_state.c b/mm/swap_state.c
> index 78d500e..c8730d7 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,
>  	pte_unmap(orig_pte);
>  }
>  
> +/**
> + * 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)
>  {

Patch
diff mbox series

diff --git a/mm/swap_state.c b/mm/swap_state.c
index 78d500e..c8730d7 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,
 	pte_unmap(orig_pte);
 }
 
+/**
+ * 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)
 {