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arch-x86,sim: Implement sched_getaffinity

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sched_getaffinity is different from other syscalls in the raw syscall
return the size of the cpumask being used to represent the CPU bit mask.

Because of this, when a library (libnuma in this case) directly called
sched_getaffinity and got a return value of 0, it errored out, thinking
that there were no CPUs available.

This implementation assumes that all CPUs are available, so it sets
all simulated CPUs in the bitmask

Change-Id: Id95c919986cc98a411877056256604f57a29f0f9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46243
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
This commit is contained in:
Kyle Roarty
2021-05-11 16:53:56 -05:00
parent 2249e4ca71
commit bcd12f301d
2 changed files with 24 additions and 1 deletions
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2
src/arch/x86/linux/syscall_tbl64.cc
View File

@@ -244,7 +244,7 @@ SyscallDescTable<EmuLinux::SyscallABI64> EmuLinux::syscallDescs64 = {
{ 201, "time", timeFunc<X86Linux64> },
{ 202, "futex", futexFunc<X86Linux64> },
{ 203, "sched_setaffinity", ignoreFunc },
{ 204, "sched_getaffinity", ignoreFunc },
{ 204, "sched_getaffinity", schedGetaffinityFunc<X86Linux64> },
{ 205, "set_thread_area" },
{ 206, "io_setup" },
{ 207, "io_destroy" },

23
src/sim/syscall_emul.hh
View File

@@ -57,6 +57,7 @@
/// application on the host machine.
#if defined(__linux__)
#include <sched.h>
#include <sys/eventfd.h>
#include <sys/statfs.h>
@@ -2603,4 +2604,26 @@ eventfdFunc(SyscallDesc *desc, ThreadContext *tc,
#endif
}
/// Target sched_getaffinity
template <class OS>
SyscallReturn
schedGetaffinityFunc(SyscallDesc *desc, ThreadContext *tc,
pid_t pid, size_t cpusetsize, VPtr<> cpu_set_mask)
{
#if defined(__linux__)
if (cpusetsize < CPU_ALLOC_SIZE(tc->getSystemPtr()->threads.size()))
return -EINVAL;
BufferArg maskBuf(cpu_set_mask, cpusetsize);
maskBuf.copyIn(tc->getVirtProxy());
for (int i = 0; i < tc->getSystemPtr()->threads.size(); i++) {
CPU_SET(i, (cpu_set_t *)maskBuf.bufferPtr());
}
maskBuf.copyOut(tc->getVirtProxy());
return CPU_ALLOC_SIZE(tc->getSystemPtr()->threads.size());
#else
warnUnsupportedOS("sched_getaffinity");
return -1;
#endif
}
#endif // __SIM_SYSCALL_EMUL_HH__