[4/5] scripts: Added Vector Length Set test helper script

Message ID 20210317023510.323258-1-naohirot@fujitsu.com
State Superseded
Delegated to: Szabolcs Nagy
Headers
Series Added optimized memcpy/memmove/memset for A64FX |

Commit Message

Naohiro Tamura March 17, 2021, 2:35 a.m. UTC
  From: Naohiro Tamura <naohirot@jp.fujitsu.com>

This patch is a test helper script to change Vector Length for child
process. This script can be used as test-wrapper for 'make check'.

Usage examples:

ubuntu@bionic:~/build$ make check subdirs=string \
test-wrapper='~/glibc/scripts/vltest.py 16'

ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 16 make test \
t=string/test-memcpy

ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 32 ./debugglibc.sh \
string/test-memmove

ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 64 ./testrun.sh
string/test-memset
---
 scripts/vltest.py | 82 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100755 scripts/vltest.py
  

Comments

Szabolcs Nagy March 29, 2021, 1:20 p.m. UTC | #1
The 03/17/2021 02:35, Naohiro Tamura wrote:
> +"""Set Scalable Vector Length test helper.
> +
> +Set Scalable Vector Length for child process.
> +
> +examples:
> +
> +ubuntu@bionic:~/build$ make check subdirs=string \
> +test-wrapper='~/glibc/scripts/vltest.py 16'
> +
> +ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 16 make test \
> +t=string/test-memcpy
> +
> +ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 32 ./debugglibc.sh \
> +string/test-memmove
> +
> +ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 64 ./testrun.sh \
> +string/test-memset
> +"""
> +import argparse
> +from ctypes import cdll, CDLL
> +import os
> +import sys
> +
> +EXIT_SUCCESS = 0
> +EXIT_FAILURE = 1
> +EXIT_UNSUPPORTED = 77
> +
> +AT_HWCAP = 16
> +HWCAP_SVE = (1 << 22)
> +
> +PR_SVE_GET_VL = 51
> +PR_SVE_SET_VL = 50
> +PR_SVE_SET_VL_ONEXEC = (1 << 18)
> +PR_SVE_VL_INHERIT = (1 << 17)
> +PR_SVE_VL_LEN_MASK = 0xffff
> +
> +def main(args):
> +    libc = CDLL("libc.so.6")
> +    if not libc.getauxval(AT_HWCAP) & HWCAP_SVE:
> +        print("CPU doesn't support SVE")
> +        sys.exit(EXIT_UNSUPPORTED)
> +
> +    libc.prctl(PR_SVE_SET_VL,
> +               args.vl[0] | PR_SVE_SET_VL_ONEXEC | PR_SVE_VL_INHERIT)
> +    os.execvp(args.args[0], args.args)
> +    print("exec system call failure")
> +    sys.exit(EXIT_FAILURE)


this only works on a (new enough) glibc based system and python's
CDLL path lookup can fail too (it does not follow the host system
configuration).

but i think there is no simple solution without compiling c code and
this seems useful, so i'm happy to have this script.
  
Naohiro Tamura March 30, 2021, 7:25 a.m. UTC | #2
Szabolcs-san,

Thank you for your review.

> > +def main(args):
> > +    libc = CDLL("libc.so.6")
> > +    if not libc.getauxval(AT_HWCAP) & HWCAP_SVE:
> > +        print("CPU doesn't support SVE")
> > +        sys.exit(EXIT_UNSUPPORTED)
> > +
> > +    libc.prctl(PR_SVE_SET_VL,
> > +               args.vl[0] | PR_SVE_SET_VL_ONEXEC |
> PR_SVE_VL_INHERIT)
> > +    os.execvp(args.args[0], args.args)
> > +    print("exec system call failure")
> > +    sys.exit(EXIT_FAILURE)
> 
> 
> this only works on a (new enough) glibc based system and python's CDLL path
> lookup can fail too (it does not follow the host system configuration).

I see, I didn't notice that.

> but i think there is no simple solution without compiling c code and this seems
> useful, so i'm happy to have this script.

OK, thanks!
Naohiro
  

Patch

diff --git a/scripts/vltest.py b/scripts/vltest.py
new file mode 100755
index 0000000000..264dfa449f
--- /dev/null
+++ b/scripts/vltest.py
@@ -0,0 +1,82 @@ 
+#!/usr/bin/python3
+# Set Scalable Vector Length test helper
+# Copyright (C) 2019-2021 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+"""Set Scalable Vector Length test helper.
+
+Set Scalable Vector Length for child process.
+
+examples:
+
+ubuntu@bionic:~/build$ make check subdirs=string \
+test-wrapper='~/glibc/scripts/vltest.py 16'
+
+ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 16 make test \
+t=string/test-memcpy
+
+ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 32 ./debugglibc.sh \
+string/test-memmove
+
+ubuntu@bionic:~/build$ ~/glibc/scripts/vltest.py 64 ./testrun.sh \
+string/test-memset
+"""
+import argparse
+from ctypes import cdll, CDLL
+import os
+import sys
+
+EXIT_SUCCESS = 0
+EXIT_FAILURE = 1
+EXIT_UNSUPPORTED = 77
+
+AT_HWCAP = 16
+HWCAP_SVE = (1 << 22)
+
+PR_SVE_GET_VL = 51
+PR_SVE_SET_VL = 50
+PR_SVE_SET_VL_ONEXEC = (1 << 18)
+PR_SVE_VL_INHERIT = (1 << 17)
+PR_SVE_VL_LEN_MASK = 0xffff
+
+def main(args):
+    libc = CDLL("libc.so.6")
+    if not libc.getauxval(AT_HWCAP) & HWCAP_SVE:
+        print("CPU doesn't support SVE")
+        sys.exit(EXIT_UNSUPPORTED)
+
+    libc.prctl(PR_SVE_SET_VL,
+               args.vl[0] | PR_SVE_SET_VL_ONEXEC | PR_SVE_VL_INHERIT)
+    os.execvp(args.args[0], args.args)
+    print("exec system call failure")
+    sys.exit(EXIT_FAILURE)
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description=
+            "Set Scalable Vector Length test helper",
+            formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+
+    # positional argument
+    parser.add_argument("vl", nargs=1, type=int,
+                        choices=range(16, 257, 16),
+                        help=('vector length '\
+                              'which is multiples of 16 from 16 to 256'))
+    # remainDer arguments
+    parser.add_argument('args', nargs=argparse.REMAINDER,
+                        help=('args '\
+                              'which is passed to child process'))
+    args = parser.parse_args()
+    main(args)