skip swapcache for super fast device
Status from this message: [merged] mm-swap-skip-swapcache-for-swapin-of-synchronous-device.patch removed from -mm tree
Get series with b4
b4 am [email protected]Versions newest first · linked by author and title
- v2 Latest posting 2/24 patches 4 repliesApplied 4/4
- v2 posting 1/24 patches 2 repliesSuperseded
- v15 patches 15 repliesSuperseded
Patches in v2 posting 2/2 All 4 applied
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/4 | zram: set BDI_CAP_STABLE_WRITES oncedrivers/ | +6 | 0 replies | Applied |
| 2/4 | bdi: introduce BDI_CAP_SYNCHRONOUS_IOdrivers/ drivers/ drivers/ +2 more | +16 | 0 replies | Applied |
| 3/4 | mm:swap: introduce SWP_SYNCHRONOUS_IOinclude/ mm/ | +5 | 0 replies | Applied |
| 4/4 | mm:swap: skip swapcache for swapin of synchronous deviceinclude/ mm/ mm/ +1 more | +57 | 4 replies | Applied |
Reviews trailers per patch
1 of 4 patches has a Reviewed-by or Acked-by.
| Patch | Sergey Senozhatsky |
|---|---|
| 1/4 | R-b |
| 2/4 | |
| 3/4 | |
| 4/4 |
Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes.
Cover letter [PATCH v2 0/4] skip swapcache for super fast device
With fast swap storage, platform want to use swap more aggressively and swap-in is crucial to application latency.
The rw_page based synchronous devices like zram, pmem and btt are such fast storage. When I profile swapin performance with zram lz4 decompress test, S/W overhead is more than 70%. Maybe, it would be bigger in nvdimm.
This patch aims for reducing swap-in latency via skipping swapcache if swap device is synchronous device like rw_page based device.
It enhances 45% my swapin test(5G sequential swapin, no readahead, from 2.41sec to 1.64sec).
Andrew, [1] is zram specific patch so could be applied separately but this patch is based on that so I include it in this series.
* From v1
* style fix
* a bug fix
* drop page-cluster based readahead off
* This regression could be solved by other patch from Huang.
http://lkml.kernel.org/r/[email protected]
Minchan Kim (4):
[1] zram: set BDI_CAP_STABLE_WRITES once
[2] bdi: introduce BDI_CAP_SYNCHRONOUS_IO
[3] mm:swap: introduce SWP_SYNCHRONOUS_IO
[4] mm:swap: skip swapcache for swapin of synchronous device
drivers/block/brd.c | 2 ++ drivers/block/zram/zram_drv.c | 16 +++++-------- drivers/nvdimm/btt.c | 3 +++ drivers/nvdimm/pmem.c | 2 ++ include/linux/backing-dev.h | 8 +++++++ include/linux/swap.h | 14 +++++++++++- mm/memory.c | 52 ++++++++++++++++++++++++++++++------------- mm/page_io.c | 6 ++--- mm/swapfile.c | 14 ++++++++---- 9 files changed, 83 insertions(+), 34 deletions(-)
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