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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/gi…
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…t/rusty/linux-2.6-lguest

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest:
  lguest: tidy up documentation
  kernel/futex.c: make 3 functions static
  unexport access_process_vm
  lguest: make async_hcall() static
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Linus Torvalds committed Nov 5, 2007
2 parents 4d20826 + 633872b commit 221d468
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Showing 5 changed files with 38 additions and 50 deletions.
69 changes: 34 additions & 35 deletions arch/x86/lguest/boot.c
Original file line number Diff line number Diff line change
Expand Up @@ -93,38 +93,7 @@ struct lguest_data lguest_data = {
};
static cycle_t clock_base;

/*G:035 Notice the lazy_hcall() above, rather than hcall(). This is our first
* real optimization trick!
*
* When lazy_mode is set, it means we're allowed to defer all hypercalls and do
* them as a batch when lazy_mode is eventually turned off. Because hypercalls
* are reasonably expensive, batching them up makes sense. For example, a
* large munmap might update dozens of page table entries: that code calls
* paravirt_enter_lazy_mmu(), does the dozen updates, then calls
* lguest_leave_lazy_mode().
*
* So, when we're in lazy mode, we call async_hypercall() to store the call for
* future processing. When lazy mode is turned off we issue a hypercall to
* flush the stored calls.
*/
static void lguest_leave_lazy_mode(void)
{
paravirt_leave_lazy(paravirt_get_lazy_mode());
hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0);
}

static void lazy_hcall(unsigned long call,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3)
{
if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)
hcall(call, arg1, arg2, arg3);
else
async_hcall(call, arg1, arg2, arg3);
}

/* async_hcall() is pretty simple: I'm quite proud of it really. We have a
/*G:037 async_hcall() is pretty simple: I'm quite proud of it really. We have a
* ring buffer of stored hypercalls which the Host will run though next time we
* do a normal hypercall. Each entry in the ring has 4 slots for the hypercall
* arguments, and a "hcall_status" word which is 0 if the call is ready to go,
Expand All @@ -134,8 +103,8 @@ static void lazy_hcall(unsigned long call,
* full and we just make the hypercall directly. This has the nice side
* effect of causing the Host to run all the stored calls in the ring buffer
* which empties it for next time! */
void async_hcall(unsigned long call,
unsigned long arg1, unsigned long arg2, unsigned long arg3)
static void async_hcall(unsigned long call, unsigned long arg1,
unsigned long arg2, unsigned long arg3)
{
/* Note: This code assumes we're uniprocessor. */
static unsigned int next_call;
Expand All @@ -161,7 +130,37 @@ void async_hcall(unsigned long call,
}
local_irq_restore(flags);
}
/*:*/

/*G:035 Notice the lazy_hcall() above, rather than hcall(). This is our first
* real optimization trick!
*
* When lazy_mode is set, it means we're allowed to defer all hypercalls and do
* them as a batch when lazy_mode is eventually turned off. Because hypercalls
* are reasonably expensive, batching them up makes sense. For example, a
* large munmap might update dozens of page table entries: that code calls
* paravirt_enter_lazy_mmu(), does the dozen updates, then calls
* lguest_leave_lazy_mode().
*
* So, when we're in lazy mode, we call async_hcall() to store the call for
* future processing. */
static void lazy_hcall(unsigned long call,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3)
{
if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)
hcall(call, arg1, arg2, arg3);
else
async_hcall(call, arg1, arg2, arg3);
}

/* When lazy mode is turned off reset the per-cpu lazy mode variable and then
* issue a hypercall to flush any stored calls. */
static void lguest_leave_lazy_mode(void)
{
paravirt_leave_lazy(paravirt_get_lazy_mode());
hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0);
}

/*G:033
* After that diversion we return to our first native-instruction
Expand Down
3 changes: 0 additions & 3 deletions include/asm-x86/lguest_hcall.h
Original file line number Diff line number Diff line change
Expand Up @@ -54,9 +54,6 @@ hcall(unsigned long call,
}
/*:*/

void async_hcall(unsigned long call,
unsigned long arg1, unsigned long arg2, unsigned long arg3);

/* Can't use our min() macro here: needs to be a constant */
#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)

Expand Down
4 changes: 0 additions & 4 deletions include/linux/futex.h
Original file line number Diff line number Diff line change
Expand Up @@ -149,10 +149,6 @@ union futex_key {
int offset;
} both;
};
int get_futex_key(u32 __user *uaddr, struct rw_semaphore *shared,
union futex_key *key);
void get_futex_key_refs(union futex_key *key);
void drop_futex_key_refs(union futex_key *key);

#ifdef CONFIG_FUTEX
extern void exit_robust_list(struct task_struct *curr);
Expand Down
11 changes: 4 additions & 7 deletions kernel/futex.c
Original file line number Diff line number Diff line change
Expand Up @@ -181,8 +181,8 @@ static inline int match_futex(union futex_key *key1, union futex_key *key2)
* For other futexes, it points to &current->mm->mmap_sem and
* caller must have taken the reader lock. but NOT any spinlocks.
*/
int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
union futex_key *key)
static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
union futex_key *key)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
Expand Down Expand Up @@ -268,14 +268,13 @@ int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
}
return err;
}
EXPORT_SYMBOL_GPL(get_futex_key);

/*
* Take a reference to the resource addressed by a key.
* Can be called while holding spinlocks.
*
*/
inline void get_futex_key_refs(union futex_key *key)
static void get_futex_key_refs(union futex_key *key)
{
if (key->both.ptr == 0)
return;
Expand All @@ -288,13 +287,12 @@ inline void get_futex_key_refs(union futex_key *key)
break;
}
}
EXPORT_SYMBOL_GPL(get_futex_key_refs);

/*
* Drop a reference to the resource addressed by a key.
* The hash bucket spinlock must not be held.
*/
void drop_futex_key_refs(union futex_key *key)
static void drop_futex_key_refs(union futex_key *key)
{
if (!key->both.ptr)
return;
Expand All @@ -307,7 +305,6 @@ void drop_futex_key_refs(union futex_key *key)
break;
}
}
EXPORT_SYMBOL_GPL(drop_futex_key_refs);

static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval)
{
Expand Down
1 change: 0 additions & 1 deletion mm/memory.c
Original file line number Diff line number Diff line change
Expand Up @@ -2748,4 +2748,3 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in

return buf - old_buf;
}
EXPORT_SYMBOL_GPL(access_process_vm);

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