From: Yang Shi <yang.shi@linux.alibaba.com>
To: ying.huang@intel.com, tim.c.chen@intel.com, minchan@kernel.org,
daniel.m.jordan@oracle.com, akpm@linux-foundation.org
Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [v5 PATCH 2/2] mm: swap: add comment for swap_vma_readahead
Date: Fri, 4 Jan 2019 03:27:53 +0800 [thread overview]
Message-ID: <1546543673-108536-2-git-send-email-yang.shi@linux.alibaba.com> (raw)
In-Reply-To: <1546543673-108536-1-git-send-email-yang.shi@linux.alibaba.com>
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(-)
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)
{
--
1.8.3.1
next prev parent reply other threads:[~2019-01-03 19:29 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-03 19:27 [v5 PATCH 1/2] mm: swap: check if swap backing device is congested or not Yang Shi
2019-01-03 19:27 ` Yang Shi [this message]
2019-01-04 2:25 ` [v5 PATCH 2/2] mm: swap: add comment for swap_vma_readahead Huang, Ying
2019-01-10 20:49 ` [v5 PATCH 1/2] mm: swap: check if swap backing device is congested or not Yang Shi
2019-01-10 23:20 ` Andrew Morton
2019-01-10 23:31 ` Andrew Morton
2019-01-10 23:40 ` Chen, Tim C
2019-01-11 0:56 ` Yang Shi
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