diff options
| 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 /include/trace | |
| 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 'include/trace')
| -rw-r--r-- | include/trace/events/ext4.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index 51eab82e897c..2a3ffa081d2c 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -122,6 +122,7 @@ TRACE_DEFINE_ENUM(EXT4_FC_REASON_MAX); TRACE_DEFINE_ENUM(CR0); TRACE_DEFINE_ENUM(CR1); +TRACE_DEFINE_ENUM(CR1_5); TRACE_DEFINE_ENUM(CR2); TRACE_DEFINE_ENUM(CR3); @@ -129,6 +130,7 @@ TRACE_DEFINE_ENUM(CR3); __print_symbolic(cr, \ { CR0, "CR0" }, \ { CR1, "CR1" }, \ + { CR1_5, "CR1.5" } \ { CR2, "CR2" }, \ { CR3, "CR3" }) |