diff options
| -rw-r--r-- | arch/ia64/kernel/entry.S | 23 | ||||
| -rw-r--r-- | include/asm-ia64/system.h | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 5 | ||||
| -rw-r--r-- | kernel/sched.c | 1 |
4 files changed, 30 insertions, 0 deletions
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S index 3c8821024509..915e12791836 100644 --- a/arch/ia64/kernel/entry.S +++ b/arch/ia64/kernel/entry.S @@ -470,6 +470,29 @@ ENTRY(load_switch_stack) br.cond.sptk.many b7 END(load_switch_stack) +GLOBAL_ENTRY(prefetch_stack) + add r14 = -IA64_SWITCH_STACK_SIZE, sp + add r15 = IA64_TASK_THREAD_KSP_OFFSET, in0 + ;; + ld8 r16 = [r15] // load next's stack pointer + lfetch.fault.excl [r14], 128 + ;; + lfetch.fault.excl [r14], 128 + lfetch.fault [r16], 128 + ;; + lfetch.fault.excl [r14], 128 + lfetch.fault [r16], 128 + ;; + lfetch.fault.excl [r14], 128 + lfetch.fault [r16], 128 + ;; + lfetch.fault.excl [r14], 128 + lfetch.fault [r16], 128 + ;; + lfetch.fault [r16], 128 + br.ret.sptk.many rp +END(prefetch_switch_stack) + GLOBAL_ENTRY(execve) mov r15=__NR_execve // put syscall number in place break __BREAK_SYSCALL diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h index 33256db4a7cf..635235fa1e32 100644 --- a/include/asm-ia64/system.h +++ b/include/asm-ia64/system.h @@ -275,6 +275,7 @@ extern void ia64_load_extra (struct task_struct *task); */ #define __ARCH_WANT_UNLOCKED_CTXSW +#define ARCH_HAS_PREFETCH_SWITCH_STACK #define ia64_platform_is(x) (strcmp(x, platform_name) == 0) void cpu_idle_wait(void); diff --git a/include/linux/sched.h b/include/linux/sched.h index ea1b5f32ec5c..c551e6a1447e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -604,6 +604,11 @@ extern int groups_search(struct group_info *group_info, gid_t grp); #define GROUP_AT(gi, i) \ ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK]) +#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK +extern void prefetch_stack(struct task_struct*); +#else +static inline void prefetch_stack(struct task_struct *t) { } +#endif struct audit_context; /* See audit.c */ struct mempolicy; diff --git a/kernel/sched.c b/kernel/sched.c index 18b95520a2e2..2632b812cf24 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2888,6 +2888,7 @@ switch_tasks: if (next == rq->idle) schedstat_inc(rq, sched_goidle); prefetch(next); + prefetch_stack(next); clear_tsk_need_resched(prev); rcu_qsctr_inc(task_cpu(prev)); |