diff options
| author | Tiwei Bie <tiwei.btw@antgroup.com> | 2025-10-27 08:18:12 +0800 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2025-10-27 16:41:15 +0100 |
| commit | 1e4ee5135d814fe4785890790cec81c3132888fb (patch) | |
| tree | b88d4e37829af3c801081a25d2a08ce23600f59c /arch/um/os-Linux/process.c | |
| parent | 9c82de55d4783e906f18219f833ad97fd8d9c5df (diff) | |
um: Add initial SMP support
Add initial symmetric multi-processing (SMP) support to UML. With
this support enabled, users can tell UML to start multiple virtual
processors, each represented as a separate host thread.
In UML, kthreads and normal threads (when running in kernel mode)
can be scheduled and executed simultaneously on different virtual
processors. However, the userspace code of normal threads still
runs within their respective single-threaded stubs.
That is, SMP support is currently available both within the kernel
and across different processes, but still remains limited within
threads of the same process in userspace.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20251027001815.1666872-6-tiwei.bie@linux.dev
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'arch/um/os-Linux/process.c')
| -rw-r--r-- | arch/um/os-Linux/process.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c index 00b49e90d05f..3a2a84ab9325 100644 --- a/arch/um/os-Linux/process.c +++ b/arch/um/os-Linux/process.c @@ -10,6 +10,8 @@ #include <errno.h> #include <signal.h> #include <fcntl.h> +#include <limits.h> +#include <linux/futex.h> #include <sys/mman.h> #include <sys/ptrace.h> #include <sys/prctl.h> @@ -189,3 +191,21 @@ void os_set_pdeathsig(void) { prctl(PR_SET_PDEATHSIG, SIGKILL); } + +int os_futex_wait(void *uaddr, unsigned int val) +{ + int r; + + CATCH_EINTR(r = syscall(__NR_futex, uaddr, FUTEX_WAIT, val, + NULL, NULL, 0)); + return r < 0 ? -errno : r; +} + +int os_futex_wake(void *uaddr) +{ + int r; + + CATCH_EINTR(r = syscall(__NR_futex, uaddr, FUTEX_WAKE, INT_MAX, + NULL, NULL, 0)); + return r < 0 ? -errno : r; +} |