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authorChao Yu <yuchao0@huawei.com>2018-08-14 17:37:25 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2018-08-21 09:13:42 +0300
commit6aa58d8ad20a3323f42274c25820a6f54192422d (patch)
tree63829cd8fe1ab14c9af2342c6d862d371613479d /Documentation
parent6f8d4455060dfb0e32dfb8e685b97caf4ed1be41 (diff)
downloadlinux-6aa58d8ad20a3323f42274c25820a6f54192422d.tar.xz
f2fs: readahead encrypted block during GC
During GC, for each encrypted block, we will read block synchronously into meta page, and then submit it into current cold data log area. So this block read model with 4k granularity can make poor performance, like migrating non-encrypted block, let's readahead encrypted block as well to improve migration performance. To implement this, we choose meta page that its index is old block address of the encrypted block, and readahead ciphertext into this page, later, if readaheaded page is still updated, we will load its data into target meta page, and submit the write IO. Note that for OPU, truncation, deletion, we need to invalid meta page after we invalid old block address, to make sure we won't load invalid data from target meta page during encrypted block migration. for ((i = 0; i < 1000; i++)) do { xfs_io -f /mnt/f2fs/dir/$i -c "pwrite 0 128k" -c "fsync"; } done for ((i = 0; i < 1000; i+=2)) do { rm /mnt/f2fs/dir/$i; } done ret = ioctl(fd, F2FS_IOC_GARBAGE_COLLECT, 0); Before: gc-6549 [001] d..1 214682.212797: block_rq_insert: 8,32 RA 32768 () 786400 + 64 [gc] gc-6549 [001] d..1 214682.212802: block_unplug: [gc] 1 gc-6549 [001] .... 214682.213892: block_bio_queue: 8,32 R 67494144 + 8 [gc] gc-6549 [001] .... 214682.213899: block_getrq: 8,32 R 67494144 + 8 [gc] gc-6549 [001] .... 214682.213902: block_plug: [gc] gc-6549 [001] d..1 214682.213905: block_rq_insert: 8,32 R 4096 () 67494144 + 8 [gc] gc-6549 [001] d..1 214682.213908: block_unplug: [gc] 1 gc-6549 [001] .... 214682.226405: block_bio_queue: 8,32 R 67494152 + 8 [gc] gc-6549 [001] .... 214682.226412: block_getrq: 8,32 R 67494152 + 8 [gc] gc-6549 [001] .... 214682.226414: block_plug: [gc] gc-6549 [001] d..1 214682.226417: block_rq_insert: 8,32 R 4096 () 67494152 + 8 [gc] gc-6549 [001] d..1 214682.226420: block_unplug: [gc] 1 gc-6549 [001] .... 214682.226904: block_bio_queue: 8,32 R 67494160 + 8 [gc] gc-6549 [001] .... 214682.226910: block_getrq: 8,32 R 67494160 + 8 [gc] gc-6549 [001] .... 214682.226911: block_plug: [gc] gc-6549 [001] d..1 214682.226914: block_rq_insert: 8,32 R 4096 () 67494160 + 8 [gc] gc-6549 [001] d..1 214682.226916: block_unplug: [gc] 1 After: gc-5678 [003] .... 214327.025906: block_bio_queue: 8,32 R 67493824 + 8 [gc] gc-5678 [003] .... 214327.025908: block_bio_backmerge: 8,32 R 67493824 + 8 [gc] gc-5678 [003] .... 214327.025915: block_bio_queue: 8,32 R 67493832 + 8 [gc] gc-5678 [003] .... 214327.025917: block_bio_backmerge: 8,32 R 67493832 + 8 [gc] gc-5678 [003] .... 214327.025923: block_bio_queue: 8,32 R 67493840 + 8 [gc] gc-5678 [003] .... 214327.025925: block_bio_backmerge: 8,32 R 67493840 + 8 [gc] gc-5678 [003] .... 214327.025932: block_bio_queue: 8,32 R 67493848 + 8 [gc] gc-5678 [003] .... 214327.025934: block_bio_backmerge: 8,32 R 67493848 + 8 [gc] gc-5678 [003] .... 214327.025941: block_bio_queue: 8,32 R 67493856 + 8 [gc] gc-5678 [003] .... 214327.025943: block_bio_backmerge: 8,32 R 67493856 + 8 [gc] gc-5678 [003] .... 214327.025953: block_bio_queue: 8,32 R 67493864 + 8 [gc] gc-5678 [003] .... 214327.025955: block_bio_backmerge: 8,32 R 67493864 + 8 [gc] gc-5678 [003] .... 214327.025962: block_bio_queue: 8,32 R 67493872 + 8 [gc] gc-5678 [003] .... 214327.025964: block_bio_backmerge: 8,32 R 67493872 + 8 [gc] gc-5678 [003] .... 214327.025970: block_bio_queue: 8,32 R 67493880 + 8 [gc] gc-5678 [003] .... 214327.025972: block_bio_backmerge: 8,32 R 67493880 + 8 [gc] gc-5678 [003] .... 214327.026000: block_bio_queue: 8,32 WS 34123776 + 2048 [gc] gc-5678 [003] .... 214327.026019: block_getrq: 8,32 WS 34123776 + 2048 [gc] gc-5678 [003] d..1 214327.026021: block_rq_insert: 8,32 R 131072 () 67493632 + 256 [gc] gc-5678 [003] d..1 214327.026023: block_unplug: [gc] 1 gc-5678 [003] d..1 214327.026026: block_rq_issue: 8,32 R 131072 () 67493632 + 256 [gc] gc-5678 [003] .... 214327.026046: block_plug: [gc] Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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