Messages in this thread | | | Subject | Re: [v4 PATCH 2/2] mm: swap: add comment for swap_vma_readahead | From | Yang Shi <> | Date | Thu, 3 Jan 2019 09:12:52 -0800 |
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On 1/2/19 11:41 PM, Huang, Ying wrote: > 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> >> --- >> 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) >> {
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