diff options
Diffstat (limited to 'arch/um/kernel/tt/process_kern.c')
| -rw-r--r-- | arch/um/kernel/tt/process_kern.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/um/kernel/tt/process_kern.c b/arch/um/kernel/tt/process_kern.c index 295c1ac817b..a9c1443fc54 100644 --- a/arch/um/kernel/tt/process_kern.c +++ b/arch/um/kernel/tt/process_kern.c @@ -51,6 +51,13 @@ void switch_to_tt(void *prev, void *next) c = 0; + /* Notice that here we "up" the semaphore on which "to" is waiting, and + * below (the read) we wait on this semaphore (which is implemented by + * switch_pipe) and go sleeping. Thus, after that, we have resumed in + * "to", and can't use any more the value of "from" (which is outdated), + * nor the value in "to" (since it was the task which stole us the CPU, + * which we don't care about). */ + err = os_write_file(to->thread.mode.tt.switch_pipe[1], &c, sizeof(c)); if(err != sizeof(c)) panic("write of switch_pipe failed, err = %d", -err); @@ -77,7 +84,7 @@ void switch_to_tt(void *prev, void *next) change_sig(SIGALRM, alrm); change_sig(SIGPROF, prof); - arch_switch(); + arch_switch_to_tt(prev_sched, current); flush_tlb_all(); local_irq_restore(flags); @@ -141,7 +148,6 @@ static void new_thread_handler(int sig) set_cmdline("(kernel thread)"); change_sig(SIGUSR1, 1); - change_sig(SIGVTALRM, 1); change_sig(SIGPROF, 1); local_irq_enable(); if(!run_kernel_thread(fn, arg, ¤t->thread.exec_buf)) |