diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2007-02-13 13:26:20 +0100 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-02-13 13:26:20 +0100 |
| commit | 464d1a78fbf8cf6c7fd970e7b3e2db50a320ce28 (patch) | |
| tree | 536d8a92976e675b484b35dec88d40c97fab8ac8 /arch/i386/kernel/traps.c | |
| parent | 54413927f022292aeccadd268fbf1c0b42129945 (diff) | |
[PATCH] i386: Convert i386 PDA code to use %fs
Convert the PDA code to use %fs rather than %gs as the segment for
per-processor data. This is because some processors show a small but
measurable performance gain for reloading a NULL segment selector (as %fs
generally is in user-space) versus a non-NULL one (as %gs generally is).
On modern processors the difference is very small, perhaps undetectable.
Some old AMD "K6 3D+" processors are noticably slower when %fs is used
rather than %gs; I have no idea why this might be, but I think they're
sufficiently rare that it doesn't matter much.
This patch also fixes the math emulator, which had not been adjusted to
match the changed struct pt_regs.
[frederik.deweerdt@gmail.com: fixit with gdb]
[mingo@elte.hu: Fix KVM too]
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Ian Campbell <Ian.Campbell@XenSource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Zachary Amsden <zach@vmware.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Diffstat (limited to 'arch/i386/kernel/traps.c')
| -rw-r--r-- | arch/i386/kernel/traps.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 0efad8aeb41..4ec21037a36 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -291,10 +291,11 @@ void show_registers(struct pt_regs *regs) int i; int in_kernel = 1; unsigned long esp; - unsigned short ss; + unsigned short ss, gs; esp = (unsigned long) (®s->esp); savesegment(ss, ss); + savesegment(gs, gs); if (user_mode_vm(regs)) { in_kernel = 0; esp = regs->esp; @@ -313,8 +314,8 @@ void show_registers(struct pt_regs *regs) regs->eax, regs->ebx, regs->ecx, regs->edx); printk(KERN_EMERG "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", regs->esi, regs->edi, regs->ebp, esp); - printk(KERN_EMERG "ds: %04x es: %04x ss: %04x\n", - regs->xds & 0xffff, regs->xes & 0xffff, ss); + printk(KERN_EMERG "ds: %04x es: %04x fs: %04x gs: %04x ss: %04x\n", + regs->xds & 0xffff, regs->xes & 0xffff, regs->xfs & 0xffff, gs, ss); printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)", TASK_COMM_LEN, current->comm, current->pid, current_thread_info(), current, current->thread_info); |