SIMD implementation of vdev_raidz generate and reconstruct routines

This is a new implementation of RAIDZ1/2/3 routines using x86_64
scalar, SSE, and AVX2 instruction sets. Included are 3 parity
generation routines (P, PQ, and PQR) and 7 reconstruction routines,
for all RAIDZ level. On module load, a quick benchmark of supported
routines will select the fastest for each operation and they will
be used at runtime. Original implementation is still present and
can be selected via module parameter.

Patch contains:
- specialized gen/rec routines for all RAIDZ levels,
- new scalar raidz implementation (unrolled),
- two x86_64 SIMD implementations (SSE and AVX2 instructions sets),
- fastest routines selected on module load (benchmark).
- cmd/raidz_test - verify and benchmark all implementations
- added raidz_test to the ZFS Test Suite

New zfs module parameters:
- zfs_vdev_raidz_impl (str): selects the implementation to use. On
  module load, the parameter will only accept first 3 options, and
  the other implementations can be set once module is finished
  loading. Possible values for this option are:
    "fastest" - use the fastest math available
    "original" - use the original raidz code
    "scalar" - new scalar impl
    "sse" - new SSE impl if available
    "avx2" - new AVX2 impl if available

See contents of `/sys/module/zfs/parameters/zfs_vdev_raidz_impl` to
get the list of supported values. If an implementation is not supported
on the system, it will not be shown. Currently selected option is
enclosed in `[]`.

Signed-off-by: Gvozden Neskovic <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #4328

3 files changed, 126 insertions, 2 deletions

diff --git a/man/man1/Makefile.am b/man/man1/Makefile.am
index 113cd0d80..5f18d1ed6 100644
--- a/man/man1/Makefile.am
+++ b/man/man1/Makefile.am
@@ -1,4 +1,4 @@
-dist_man_MANS = zhack.1 zpios.1 ztest.1
+dist_man_MANS = zhack.1 zpios.1 ztest.1 raidz_test.1
 EXTRA_DIST = cstyle.1
 
 install-data-local:
diff --git a/man/man1/raidz_test.1 b/man/man1/raidz_test.1
new file mode 100644
index 000000000..90d858d5b
--- /dev/null
+++ b/man/man1/raidz_test.1
@@ -0,0 +1,97 @@
+'\" t
+.\"
+.\" CDDL HEADER START
+.\"
+.\" The contents of this file are subject to the terms of the
+.\" Common Development and Distribution License (the "License").
+.\" You may not use this file except in compliance with the License.
+.\"
+.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+.\" or http://www.opensolaris.org/os/licensing.
+.\" See the License for the specific language governing permissions
+.\" and limitations under the License.
+.\"
+.\" When distributing Covered Code, include this CDDL HEADER in each
+.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+.\" If applicable, add the following below this CDDL HEADER, with the
+.\" fields enclosed by brackets "[]" replaced with your own identifying
+.\" information: Portions Copyright [yyyy] [name of copyright owner]
+.\"
+.\" CDDL HEADER END
+.\"
+.\"
+.\" Copyright (c) 2016 Gvozden Nešković. All rights reserved.
+.\"
+.TH raidz_test 1 "2016" "ZFS on Linux" "User Commands"
+
+.SH NAME
+\fBraidz_test\fR \- raidz implementation verification and bencmarking tool
+.SH SYNOPSIS
+.LP
+.BI "raidz_test <options>"
+.SH DESCRIPTION
+.LP
+This manual page documents briefly the \fBraidz_test\fR command.
+.LP
+Purpose of this tool is to run all supported raidz implementation and verify
+results of all methods. Tool also contains a parameter sweep option where all
+parameters affecting RAIDZ block are verified (like ashift size, data offset,
+data size, etc...).
+The tool also supports a benchmarking mode using -B option.
+.SH OPTION
+.HP
+.BI "\-h" ""
+.IP
+Print a help summary.
+.HP
+.BI "\-a" " ashift (default: 9)"
+.IP
+Ashift value.
+.HP
+.BI "\-o" " zio_off_shift" " (default: 0)"
+.IP
+Zio offset for raidz block. Offset value is 1 << (zio_off_shift)
+.HP
+.BI "\-d" " raidz_data_disks" " (default: 8)"
+.IP
+Number of raidz data disks to use. Additional disks for parity will be used
+during testing.
+.HP
+.BI "\-s" " zio_size_shift" " (default: 19)"
+.IP
+Size of data for raidz block. Size is 1 << (zio_size_shift).
+.HP
+.BI "\-S(weep)"
+.IP
+Sweep parameter space while verifying the raidz implementations. This option
+will exhaust all most of valid values for -a -o -d -s options. Runtime using
+this option will be long.
+.HP
+.BI "\-t(imeout)"
+.IP
+Wall time for sweep test in seconds. The actual runtime could be longer.
+.HP
+.BI "\-B(enchmark)"
+.IP
+This options starts the benchmark mode. All implementations are benchmarked
+using increasing per disk data size. Results are given as throughput per disk,
+measured in MiB/s.
+.HP
+.BI "\-v(erbose)"
+.IP
+Increase verbosity.
+.HP
+.BI "\-T(est the test)"
+.IP
+Debugging option. When this option is specified tool is supposed to fail
+all tests. This is to check if tests would properly verify bit-exactness.
+.HP
+.BI "\-D(ebug)"
+.IP
+Debugging option. Specify to attach gdb when SIGSEGV or SIGABRT are received.
+.HP
+
+.SH "SEE ALSO"
+.BR "ztest (1)"
+.SH "AUTHORS"
+vdev_raidz, created for ZFS on Linux by Gvozden Nešković <[email protected]>
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5
index 664a806c0..e8c363eba 100644
--- a/man/man5/zfs-module-parameters.5
+++ b/man/man5/zfs-module-parameters.5
@@ -1677,6 +1677,33 @@ Default value: \fB4,096\fR.
 .sp
 .ne 2
 .na
+\fBzfs_vdev_raidz_impl\fR (string)
+.ad
+.RS 12n
+Parameter for selecting raidz implementation to use.
+
+Options marked (always) below may be selected on module load as they are
+supported on all systems.
+The remaining options may only be set after the module is loaded, as they
+are available only if the implementations are compiled in and supported
+on the running system.
+
+Once the module is loaded, the content of
+/sys/module/zfs/parameters/zfs_vdev_raidz_impl will show available options
+with the currently selected one enclosed in [].
+Possible options are:
+  fastest  - (always) implementation selected using built-in benchmark
+  original - (always) original raidz implementation
+  scalar   - (always) scalar raidz implementation
+  sse      - implementation using SSE instruction set (64bit x86 only)
+  avx2     - implementation using AVX2 instruction set (64bit x86 only)
+.sp
+Default value: \fBfastest\fR.
+.RE
+
+.sp
+.ne 2
+.na
 \fBzfs_zevent_cols\fR (int)
 .ad
 .RS 12n
@@ -1739,7 +1766,7 @@ Default value: \fB1,048,576\fR.
 .ad
 .RS 12n
 A zevent will be logged if a ZIO operation takes more than N milliseconds to
-complete. Note that this is only a logging facility, not a timeout on 
+complete. Note that this is only a logging facility, not a timeout on
 operations.
 .sp
 Default value: \fB30,000\fR.