linux/include/asm-um/mmu_context.h
Benjamin LaHaise c40504e87e [PATCH] uml: tlb flushing fix
This patch fixes a fairly serious tlb flushing bug that makes aio use under
uml very unreliable -- SEGVs, Oops and panic()s occur as a result of stale
tlb entires being used by uml when aio switches mms due to the fact that
uml does not implement the activate_mm() hook.  This patch introduces a
simple but correct approach (read: hammer) for implementing activate_mm()
in uml by doing a force_flush_all() if the new mm is different from old.
With this patch in place, uml is able to succeed at the aio test case that
was randomly faulting for me before.

Cc: Jeff Dike <jdike@addtoit.com>
Cc: <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-12 16:01:01 -07:00

80 lines
1.9 KiB
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#ifndef __UM_MMU_CONTEXT_H
#define __UM_MMU_CONTEXT_H
#include "linux/sched.h"
#include "linux/config.h"
#include "choose-mode.h"
#include "um_mmu.h"
#define get_mmu_context(task) do ; while(0)
#define activate_context(tsk) do ; while(0)
#define deactivate_mm(tsk,mm) do { } while (0)
extern void force_flush_all(void);
static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
{
if (old != new)
force_flush_all();
}
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned cpu = smp_processor_id();
if(prev != next){
cpu_clear(cpu, prev->cpu_vm_mask);
cpu_set(cpu, next->cpu_vm_mask);
if(next != &init_mm)
CHOOSE_MODE((void) 0,
switch_mm_skas(&next->context.skas.id));
}
}
static inline void enter_lazy_tlb(struct mm_struct *mm,
struct task_struct *tsk)
{
}
extern int init_new_context_skas(struct task_struct *task,
struct mm_struct *mm);
static inline int init_new_context_tt(struct task_struct *task,
struct mm_struct *mm)
{
return(0);
}
static inline int init_new_context(struct task_struct *task,
struct mm_struct *mm)
{
return(CHOOSE_MODE_PROC(init_new_context_tt, init_new_context_skas,
task, mm));
}
extern void destroy_context_skas(struct mm_struct *mm);
static inline void destroy_context(struct mm_struct *mm)
{
CHOOSE_MODE((void) 0, destroy_context_skas(mm));
}
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
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* Local variables:
* c-file-style: "linux"
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*/