Re: [v4 PATCH 2/2] mm: swap: add comment for swap_vma_readahead

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 1/2/19 11:41 PM, Huang, Ying wrote:
Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> writes:

swap_vma_readahead()'s comment is missed, just add it.

Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
---
  mm/swap_state.c | 17 +++++++++++++++++
  1 file changed, 17 insertions(+)

diff --git a/mm/swap_state.c b/mm/swap_state.c
index 78d500e..dd8f698 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -698,6 +698,23 @@ static void swap_ra_info(struct vm_fault *vmf,
  	pte_unmap(orig_pte);
  }
+/**
+ * swap_vm_readahead - swap in pages in hope we need them soon
s/swap_vm_readahead/swap_vma_readahead/

+ * @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.
+ *
+ * This has been extended to use the NUMA policies from the mm triggering
+ * the readahead.
What is this?  I know you copy it from swap_cluster_readahead(), but we
have only one mm for vma readahead.

Aha, I see. Actually I was confused by this too, so just copied from swap_cluster_readahead.


+ * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL.
Better to make it explicit that your are talking about mmap_sem?

Sure.

Thanks,
Yang


Best Regards,
Huang, Ying

+ *
+ */
  static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
  				       struct vm_fault *vmf)
  {




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux