linux-dev/tools/testing/selftests/powerpc/benchmarks/context_switch.c, branch linus/master

selftests/powerpc: Don't touch VMX/VSX on older CPUs

2020-09-08T12:24:10Z

If we're running on a CPU without VMX/VSX then don't touch them. This is fragile, the compiler could spill a VMX/VSX register and break the test anyway. But in practice it seems to work, ie. the test runs to completion on a system without VSX with this change. Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200819015727.1977134-8-mpe@ellerman.id.au

selftests/powerpc: Fix CPU affinity for child process

2020-07-29T12:30:34Z

On systems with large number of cpus, test fails trying to set affinity by calling sched_setaffinity() with smaller size for affinity mask. This patch fixes it by making sure that the size of allocated affinity mask is dependent on the number of CPUs as reported by get_nprocs(). Fixes: 00b7ec5c9cf3 ("selftests/powerpc: Import Anton's context_switch2 benchmark") Reported-by: Shirisha Ganta Signed-off-by: Sandipan Das Signed-off-by: Harish Reviewed-by: Kamalesh Babulal Reviewed-by: Satheesh Rajendran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200609081423.529664-1-harish@linux.ibm.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

selftests/powerpc: context_switch: Fix pthread errors

2017-10-13T08:41:56Z

Turns out pthreads returns an errno and doesn't set errno. This doesn't play well with perror(). Signed-off-by: Cyril Bur Signed-off-by: Michael Ellerman

selftests/powerpc: context_switch use private futexes with threads

2017-06-05T06:55:01Z

This reduces overhead of mutex locking and increases context switch rate significantly (which helps to measure and profile the context switch path). Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

selftests/powerpc: Move shared headers into new include dir

2016-11-17T06:11:47Z

There are some functions, especially register related, which can be shared across multiple selftests/powerpc test directories. This patch creates a new include directory to store those shared files, so that the file layout becomes more neat. Signed-off-by: Simon Guo [mpe: Reworked to move the headers only] Signed-off-by: Michael Ellerman

selftests/powerpc: Fix generation of vector instructions/types in context_switch

2016-07-05T13:49:50Z

Currently it doesn't appear the resulting binary actually uses any Altivec or VSX instructions the solution is to explicitly tell GCC to use vector instructions and use vector types in the code. Part of this this issue can be GCC version specific: GCC 4.9.x is happy to use Altivec and VSX instructions if altivec.h is includedi (and possibly if vector types are used), this also means that 4.9.x will use VSX instructions even if only -maltivec is passed. It is also possible that Altivec instructions will be used even without -maltivec or -mabi=altivec. GCC 5.2.x complains about the lack of -maltivec parameter if altivec.h is included and will not use VSX unless -mvsx is present on commandline. GCC 5.3.0 has a regression that means __attribute__((__target__("no-vsx")) fails to build. A fix is targeted for 5.4. Furthermore LTO (Link Time Optimisation) doesn't play well with __attribute__((__target__("no-vsx")), LTO can cause GCC to forget about the attribute and compile with VSX instructions regardless. Be wary when enabling -flfo for this test. Signed-off-by: Cyril Bur Signed-off-by: Michael Ellerman

selftests/powerpc: Fix usage message in context_switch

2016-07-05T13:49:49Z

When we inverted the behaviour of the flags we forgot to update the usage message. Fixes: 51c21e72eb99 ("selftests/powerpc: Make context_switch touch FP/altivec/vector by default") Signed-off-by: Cyril Bur Signed-off-by: Michael Ellerman

selftests/powerpc: Make context_switch touch FP/altivec/vector by default

2015-12-16T23:46:43Z

Simply because it touches more code paths that way, and therefore tests more things. Signed-off-by: Michael Ellerman Acked-by: Anton Blanchard

selftests/powerpc: Make context_switch do something with no args

2015-12-16T23:46:42Z

For ease of use make the context_switch test do something useful when called with no arguments. Default to a 30 second run, using threads, doing yield, and use any online cpu. Make it print out what it's doing to avoid confusion. Signed-off-by: Michael Ellerman Acked-by: Anton Blanchard