6aa58d8ad2
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.