Messages in this thread Patch in this message | | | Date | Mon, 2 Jun 2014 16:26:13 -0700 (PDT) | From | Hugh Dickins <> | Subject | Re: [PATCH] swap: Delete the "last_in_cluster < scan_base" loop in the body of scan_swap_map() |
| |
On Mon, 2 Jun 2014, Chen Yucong wrote:
> From commit ebc2a1a69111, we can find that all SWP_SOLIDSTATE "seek is cheap"(SSD case) > has already gone to si->cluster_info scan_swap_map_try_ssd_cluster() route. So that the > "last_in_cluster < scan_base" loop in the body of scan_swap_map() has already become a > dead code snippet, and it should have been deleted. > > This patch is to delete the redundant loop as Hugh and Shaohua suggested. > > Signed-off-by: Chen Yucong <slaoub@gmail.com>
That is very nice, thank you.
Acked-by: Hugh Dickins <hughd@google.com>
But it does beg for just a little more: perhaps Andrew can kindly fold in: ---
mm/swapfile.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
--- chen/mm/swapfile.c 2014-06-02 15:55:44.812368186 -0700 +++ hugh/mm/swapfile.c 2014-06-02 16:15:20.344396124 -0700 @@ -505,13 +505,10 @@ static unsigned long scan_swap_map(struc /* * If seek is expensive, start searching for new cluster from * start of partition, to minimize the span of allocated swap. - * But if seek is cheap, search from our current position, so - * that swap is allocated from all over the partition: if the - * Flash Translation Layer only remaps within limited zones, - * we don't want to wear out the first zone too quickly. + * If seek is cheap, that is the SWP_SOLIDSTATE si->cluster_info + * case, just handled by scan_swap_map_try_ssd_cluster() above. */ - if (!(si->flags & SWP_SOLIDSTATE)) - scan_base = offset = si->lowest_bit; + scan_base = offset = si->lowest_bit; last_in_cluster = offset + SWAPFILE_CLUSTER - 1; /* Locate the first empty (unaligned) cluster */
| |