X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Fprocess.c;h=abf49a36473f756db5357c209e21e50f970c12d5;hb=refs%2Fheads%2Fvserver;hp=ea4ffbbda71dc66fa955fe2a7db563cea4a7c209;hpb=e0ff8aa1acd079b70e796571917ae0449b7c465b;p=linux-2.6.git diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index ea4ffbbda..abf49a364 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -55,6 +56,7 @@ #include #include +#include asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); @@ -98,22 +100,23 @@ EXPORT_SYMBOL(enable_hlt); */ void default_idle(void) { - local_irq_enable(); - if (!hlt_counter && boot_cpu_data.hlt_works_ok) { current_thread_info()->status &= ~TS_POLLING; - smp_mb__after_clear_bit(); - while (!need_resched()) { - local_irq_disable(); - if (!need_resched()) - safe_halt(); - else - local_irq_enable(); - } + /* + * TS_POLLING-cleared state must be visible before we + * test NEED_RESCHED: + */ + smp_mb(); + + local_irq_disable(); + if (!need_resched()) + safe_halt(); /* enables interrupts racelessly */ + else + local_irq_enable(); current_thread_info()->status |= TS_POLLING; } else { - while (!need_resched()) - cpu_relax(); + /* loop is done by the caller */ + cpu_relax(); } } #ifdef CONFIG_APM_MODULE @@ -127,14 +130,7 @@ EXPORT_SYMBOL(default_idle); */ static void poll_idle (void) { - local_irq_enable(); - - asm volatile( - "2:" - "testl %0, %1;" - "rep; nop;" - "je 2b;" - : : "i"(_TIF_NEED_RESCHED), "m" (current_thread_info()->flags)); + cpu_relax(); } #ifdef CONFIG_HOTPLUG_CPU @@ -204,7 +200,7 @@ void cpu_idle(void) void cpu_idle_wait(void) { unsigned int cpu, this_cpu = get_cpu(); - cpumask_t map; + cpumask_t map, tmp = current->cpus_allowed; set_cpus_allowed(current, cpumask_of_cpu(this_cpu)); put_cpu(); @@ -226,6 +222,8 @@ void cpu_idle_wait(void) } cpus_and(map, map, cpu_online_map); } while (!cpus_empty(map)); + + set_cpus_allowed(current, tmp); } EXPORT_SYMBOL_GPL(cpu_idle_wait); @@ -235,20 +233,27 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait); * We execute MONITOR against need_resched and enter optimized wait state * through MWAIT. Whenever someone changes need_resched, we would be woken * up from MWAIT (without an IPI). + * + * New with Core Duo processors, MWAIT can take some hints based on CPU + * capability. */ -static void mwait_idle(void) +void mwait_idle_with_hints(unsigned long eax, unsigned long ecx) { - local_irq_enable(); - - while (!need_resched()) { + if (!need_resched()) { __monitor((void *)¤t_thread_info()->flags, 0, 0); smp_mb(); - if (need_resched()) - break; - __mwait(0, 0); + if (!need_resched()) + __mwait(eax, ecx); } } +/* Default MONITOR/MWAIT with no hints, used for default C1 state */ +static void mwait_idle(void) +{ + local_irq_enable(); + mwait_idle_with_hints(0, 0); +} + void __devinit select_idle_routine(const struct cpuinfo_x86 *c) { if (cpu_has(c, X86_FEATURE_MWAIT)) { @@ -289,22 +294,24 @@ void show_regs(struct pt_regs * regs) unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L; printk("\n"); - printk("Pid: %d, comm: %20s\n", current->pid, current->comm); - printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id()); + printk("Pid: %d[#%u], comm: %20s\n", + current->pid, current->xid, current->comm); + printk("EIP: %04x:[<%08lx>] CPU: %d\n", + 0xffff & regs->xcs,regs->eip, smp_processor_id()); print_symbol("EIP is at %s\n", regs->eip); if (user_mode_vm(regs)) printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp); printk(" EFLAGS: %08lx %s (%s %.*s)\n", - regs->eflags, print_tainted(), system_utsname.release, - (int)strcspn(system_utsname.version, " "), - system_utsname.version); + regs->eflags, print_tainted(), init_utsname()->release, + (int)strcspn(init_utsname()->version, " "), + init_utsname()->version); printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n", regs->eax,regs->ebx,regs->ecx,regs->edx); printk("ESI: %08lx EDI: %08lx EBP: %08lx", regs->esi, regs->edi, regs->ebp); - printk(" DS: %04x ES: %04x\n", - 0xffff & regs->xds,0xffff & regs->xes); + printk(" DS: %04x ES: %04x GS: %04x\n", + 0xffff & regs->xds,0xffff & regs->xes, 0xffff & regs->xgs); cr0 = read_cr0(); cr2 = read_cr2(); @@ -327,7 +334,6 @@ extern void kernel_thread_helper(void); int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) { struct pt_regs regs; - int err; memset(®s, 0, sizeof(regs)); @@ -336,16 +342,15 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) regs.xds = __USER_DS; regs.xes = __USER_DS; + regs.xgs = __KERNEL_PDA; regs.orig_eax = -1; regs.eip = (unsigned long) kernel_thread_helper; - regs.xcs = __KERNEL_CS; + regs.xcs = __KERNEL_CS | get_kernel_rpl(); regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2; /* Ok, create the new process.. */ - err = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); - if (err == 0) /* terminate kernel stack */ - task_pt_regs(current)->eip = 0; - return err; + return do_fork(flags | CLONE_VM | CLONE_UNTRACED | CLONE_KTHREAD, + 0, ®s, 0, NULL, NULL); } EXPORT_SYMBOL(kernel_thread); @@ -424,17 +429,15 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp, p->thread.eip = (unsigned long) ret_from_fork; savesegment(fs,p->thread.fs); - savesegment(gs,p->thread.gs); tsk = current; if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) { - p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); + p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr, + IO_BITMAP_BYTES, GFP_KERNEL); if (!p->thread.io_bitmap_ptr) { p->thread.io_bitmap_max = 0; return -ENOMEM; } - memcpy(p->thread.io_bitmap_ptr, tsk->thread.io_bitmap_ptr, - IO_BITMAP_BYTES); set_tsk_thread_flag(p, TIF_IO_BITMAP); } @@ -502,7 +505,7 @@ void dump_thread(struct pt_regs * regs, struct user * dump) dump->regs.ds = regs->xds; dump->regs.es = regs->xes; savesegment(fs,dump->regs.fs); - savesegment(gs,dump->regs.gs); + dump->regs.gs = regs->xgs; dump->regs.orig_eax = regs->orig_eax; dump->regs.eip = regs->eip; dump->regs.cs = regs->xcs; @@ -644,22 +647,27 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas if (next_p->mm) load_user_cs_desc(cpu, next_p->mm); + + /* we're going to use this soon, after a few expensive things */ + if (next_p->fpu_counter > 5) + prefetch(&next->i387.fxsave); + /* * Reload esp0. */ load_esp0(tss, next); /* - * Save away %fs and %gs. No need to save %es and %ds, as - * those are always kernel segments while inside the kernel. - * Doing this before setting the new TLS descriptors avoids - * the situation where we temporarily have non-reloadable - * segments in %fs and %gs. This could be an issue if the - * NMI handler ever used %fs or %gs (it does not today), or - * if the kernel is running inside of a hypervisor layer. + * Save away %fs. No need to save %gs, as it was saved on the + * stack on entry. No need to save %es and %ds, as those are + * always kernel segments while inside the kernel. Doing this + * before setting the new TLS descriptors avoids the situation + * where we temporarily have non-reloadable segments in %fs + * and %gs. This could be an issue if the NMI handler ever + * used %fs or %gs (it does not today), or if the kernel is + * running inside of a hypervisor layer. */ savesegment(fs, prev->fs); - savesegment(gs, prev->gs); /* * Load the per-thread Thread-Local Storage descriptor. @@ -667,22 +675,14 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas load_TLS(next, cpu); /* - * Restore %fs and %gs if needed. + * Restore %fs if needed. * - * Glibc normally makes %fs be zero, and %gs is one of - * the TLS segments. + * Glibc normally makes %fs be zero. */ if (unlikely(prev->fs | next->fs)) loadsegment(fs, next->fs); - if (prev->gs | next->gs) - loadsegment(gs, next->gs); - - /* - * Restore IOPL if needed. - */ - if (unlikely(prev->iopl != next->iopl)) - set_iopl_mask(next->iopl); + write_pda(pcurrent, next_p); /* * Now maybe handle debug registers and/or IO bitmaps @@ -693,6 +693,13 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas disable_tsc(prev_p, next_p); + /* If the task has used fpu the last 5 timeslices, just do a full + * restore of the math state immediately to avoid the trap; the + * chances of needing FPU soon are obviously high now + */ + if (next_p->fpu_counter > 5) + math_state_restore(); + return prev_p; } @@ -748,9 +755,6 @@ asmlinkage int sys_execve(struct pt_regs regs) (char __user * __user *) regs.edx, ®s); if (error == 0) { - task_lock(current); - current->ptrace &= ~PT_DTRACE; - task_unlock(current); /* Make sure we don't return using sysenter.. */ set_thread_flag(TIF_IRET); } @@ -902,7 +906,7 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info) unsigned long arch_align_stack(unsigned long sp) { - if (randomize_va_space) + if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) sp -= get_random_int() % 8192; return sp & ~0xf; }