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| author | Ojaswin Mujoo <ojaswin@linux.ibm.com> | 2023-05-30 18:03:49 +0530 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-06-26 19:34:56 -0400 |
| commit | 7e170922f06bf46effa7c57f6035fc463d6edc7e (patch) | |
| tree | 60306c92b8d9cbbbc3764edb53662ad9bd38f9e8 /io_uring/poll.c | |
| parent | 856d865c178b4fbf4c629d5a7d0df9352d123280 (diff) | |
ext4: Add allocation criteria 1.5 (CR1_5)
CR1_5 aims to optimize allocations which can't be satisfied in CR1. The
fact that we couldn't find a group in CR1 suggests that it would be
difficult to find a continuous extent to compleltely satisfy our
allocations. So before falling to the slower CR2, in CR1.5 we
proactively trim the the preallocations so we can find a group with
(free / fragments) big enough. This speeds up our allocation at the
cost of slightly reduced preallocation.
The patch also adds a new sysfs tunable:
* /sys/fs/ext4/<partition>/mb_cr1_5_max_trim_order
This controls how much CR1.5 can trim a request before falling to CR2.
For example, for a request of order 7 and max trim order 2, CR1.5 can
trim this upto order 5.
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/150fdf65c8e4cc4dba71e020ce0859bcf636a5ff.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'io_uring/poll.c')
0 files changed, 0 insertions, 0 deletions