mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-26 13:30:55 +07:00
464d1a78fb
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>
72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
#ifndef __I386_SCHED_H
|
|
#define __I386_SCHED_H
|
|
|
|
#include <asm/desc.h>
|
|
#include <asm/atomic.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
/*
|
|
* Used for LDT copy/destruction.
|
|
*/
|
|
int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
|
|
void destroy_context(struct mm_struct *mm);
|
|
|
|
|
|
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
unsigned cpu = smp_processor_id();
|
|
if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
|
|
per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_LAZY;
|
|
#endif
|
|
}
|
|
|
|
static inline void switch_mm(struct mm_struct *prev,
|
|
struct mm_struct *next,
|
|
struct task_struct *tsk)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
if (likely(prev != next)) {
|
|
/* stop flush ipis for the previous mm */
|
|
cpu_clear(cpu, prev->cpu_vm_mask);
|
|
#ifdef CONFIG_SMP
|
|
per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
|
|
per_cpu(cpu_tlbstate, cpu).active_mm = next;
|
|
#endif
|
|
cpu_set(cpu, next->cpu_vm_mask);
|
|
|
|
/* Re-load page tables */
|
|
load_cr3(next->pgd);
|
|
|
|
/*
|
|
* load the LDT, if the LDT is different:
|
|
*/
|
|
if (unlikely(prev->context.ldt != next->context.ldt))
|
|
load_LDT_nolock(&next->context);
|
|
}
|
|
#ifdef CONFIG_SMP
|
|
else {
|
|
per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
|
|
BUG_ON(per_cpu(cpu_tlbstate, cpu).active_mm != next);
|
|
|
|
if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
|
|
/* We were in lazy tlb mode and leave_mm disabled
|
|
* tlb flush IPI delivery. We must reload %cr3.
|
|
*/
|
|
load_cr3(next->pgd);
|
|
load_LDT_nolock(&next->context);
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#define deactivate_mm(tsk, mm) \
|
|
asm("movl %0,%%gs": :"r" (0));
|
|
|
|
#define activate_mm(prev, next) \
|
|
switch_mm((prev),(next),NULL)
|
|
|
|
#endif
|