diff options
| author | Tyler J. Stachecki <[email protected]> | 2016-06-23 23:32:40 -0400 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2016-07-15 10:42:35 -0700 |
| commit | 35a76a0366372d89a0f1ac3cebd5bc7646aadec3 (patch) | |
| tree | c5a736ca9254afde0f65a0991efd9da216fa112a /man | |
| parent | dfbc86309fd8ebb70a55cafa876320dc1ea8e833 (diff) | |
Implementation of SSE optimized Fletcher-4
Builds off of 1eeb4562 (Implementation of AVX2 optimized Fletcher-4)
This commit adds another implementation of the Fletcher-4 algorithm.
It is automatically selected at module load if it benchmarks higher
than all other available implementations.
The module benchmark was also amended to analyze the performance of
the byteswap-ed version of Fletcher-4, as well as the non-byteswaped
version. The average performance of the two is used to select the
the fastest implementation available on the host system.
Adds a pair of fields to an existing zcommon module parameter:
- zfs_fletcher_4_impl (str)
"sse2" - new SSE2 implementation if available
"ssse3" - new SSSE3 implementation if available
Signed-off-by: Tyler J. Stachecki <[email protected]>
Signed-off-by: Gvozden Neskovic <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #4789
Diffstat (limited to 'man')
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 7b0199de2..79855e72d 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -838,11 +838,15 @@ Default value: \fB67,108,864\fR. .RS 12n Select a fletcher 4 implementation. .sp -Supported selectors are: \fBfastest\fR, \fBscalar\fR, and \fBavx2\fR when -AVX2 is supported by the processor. If multiple implementations of fletcher 4 -are available the \fBfastest\fR will be chosen using a micro benchmark. -Selecting \fBscalar\fR results in the original CPU based calculation being -used, \fBavx2\fR uses the AVX2 vector instructions to compute a fletcher 4. +Supported selectors are: \fBfastest\fR, \fBscalar\fR, \fBsse2\fR, \fBssse3\fR, +and \fBavx2\fR. All of the selectors except \fBfastest\fR and \fBscalar\fR +require instruction set extensions to be available and will only appear if ZFS +detects that they are present at runtime. If multiple implementations of +fletcher 4 are available, the \fBfastest\fR will be chosen using a micro +benchmark. Selecting \fBscalar\fR results in the original CPU based calculation +being used. Selecting any option other than \fBfastest\fR and \fBscalar\fR +results in vector instructions from the respective CPU instruction set being +used. .sp Default value: \fBfastest\fR. .RE |