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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-09-06 12:28:24 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-09-27 09:18:12 -0300 |
| commit | 33099d72e41cf8a129b362e9709eb2be9372d844 (patch) | |
| tree | eb1a795c7b6c276157dadd58f4d720672efe9402 /posix/Makefile | |
| parent | 11a02b035b464ab6813676adfd19c4a59c36d907 (diff) | |
| download | glibc-33099d72e41cf8a129b362e9709eb2be9372d844.zip glibc-33099d72e41cf8a129b362e9709eb2be9372d844.tar.gz glibc-33099d72e41cf8a129b362e9709eb2be9372d844.tar.bz2 | |
linux: Simplify get_nprocs
This patch simplifies the memory allocation code and uses the sched
routines instead of reimplement it. This still uses a stack
allocation buffer, so it can be used on malloc initialization code.
Linux currently supports at maximum of 4096 cpus for most architectures:
$ find -iname Kconfig | xargs git grep -A10 -w NR_CPUS | grep -w range
arch/alpha/Kconfig- range 2 32
arch/arc/Kconfig- range 2 4096
arch/arm/Kconfig- range 2 16 if DEBUG_KMAP_LOCAL
arch/arm/Kconfig- range 2 32 if !DEBUG_KMAP_LOCAL
arch/arm64/Kconfig- range 2 4096
arch/csky/Kconfig- range 2 32
arch/hexagon/Kconfig- range 2 6 if SMP
arch/ia64/Kconfig- range 2 4096
arch/mips/Kconfig- range 2 256
arch/openrisc/Kconfig- range 2 32
arch/parisc/Kconfig- range 2 32
arch/riscv/Kconfig- range 2 32
arch/s390/Kconfig- range 2 512
arch/sh/Kconfig- range 2 32
arch/sparc/Kconfig- range 2 32 if SPARC32
arch/sparc/Kconfig- range 2 4096 if SPARC64
arch/um/Kconfig- range 1 1
arch/x86/Kconfig-# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
arch/x86/Kconfig- range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
arch/xtensa/Kconfig- range 2 32
With x86 supporting 8192:
arch/x86/Kconfig
976 config NR_CPUS_RANGE_END
977 int
978 depends on X86_64
979 default 8192 if SMP && CPUMASK_OFFSTACK
980 default 512 if SMP && !CPUMASK_OFFSTACK
981 default 1 if !SMP
So using a maximum of 32k cpu should cover all cases (and I would
expect once we start to have many more CPUs that Linux would provide
a more straightforward way to query for such information).
A test is added to check if sched_getaffinity can successfully return
with large buffers.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Diffstat (limited to 'posix/Makefile')
| -rw-r--r-- | posix/Makefile | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/posix/Makefile b/posix/Makefile index a522977..61fcdf0 100644 --- a/posix/Makefile +++ b/posix/Makefile @@ -107,7 +107,8 @@ tests := test-errno tstgetopt testfnm runtests runptests \ tst-sysconf-empty-chroot tst-glob_symlinks tst-fexecve \ tst-glob-tilde test-ssize-max tst-spawn4 bug-regex37 \ bug-regex38 tst-regcomp-truncated tst-spawn-chdir \ - tst-wordexp-nocmd tst-execveat tst-spawn5 + tst-wordexp-nocmd tst-execveat tst-spawn5 \ + tst-sched_getaffinity # Test for the glob symbol version that was replaced in glibc 2.27. ifeq ($(have-GLIBC_2.26)$(build-shared),yesyes) |