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x86, bts: memory accounting

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Impact: move the BTS buffer accounting to the mlock bucket

Add alloc_locked_buffer() and free_locked_buffer() functions to mm/mlock.c
to kalloc a buffer and account the locked memory to current.

Account the memory for the BTS buffer to the tracer.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Markus Metzger 2008-12-19 15:17:02 +01:00 committed by Ingo Molnar
parent bf53de907d
commit c5dee6177f
3 changed files with 81 additions and 11 deletions
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45
arch/x86/kernel/ptrace.c
View File

@ -650,6 +650,24 @@ static int ptrace_bts_drain(struct task_struct *child,
return drained;
}
static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
{
child->bts_buffer = alloc_locked_buffer(size);
if (!child->bts_buffer)
return -ENOMEM;
child->bts_size = size;
return 0;
}
static void ptrace_bts_free_buffer(struct task_struct *child)
{
free_locked_buffer(child->bts_buffer, child->bts_size);
child->bts_buffer = NULL;
child->bts_size = 0;
}
static int ptrace_bts_config(struct task_struct *child,
long cfg_size,
const struct ptrace_bts_config __user *ucfg)
@ -679,14 +697,13 @@ static int ptrace_bts_config(struct task_struct *child,
if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
(cfg.size != child->bts_size)) {
kfree(child->bts_buffer);
int error;
child->bts_size = cfg.size;
child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
if (!child->bts_buffer) {
child->bts_size = 0;
return -ENOMEM;
}
ptrace_bts_free_buffer(child);
error = ptrace_bts_allocate_buffer(child, cfg.size);
if (error < 0)
return error;
}
if (cfg.flags & PTRACE_BTS_O_TRACE)
@ -701,10 +718,8 @@ static int ptrace_bts_config(struct task_struct *child,
if (IS_ERR(child->bts)) {
int error = PTR_ERR(child->bts);
kfree(child->bts_buffer);
ptrace_bts_free_buffer(child);
child->bts = NULL;
child->bts_buffer = NULL;
child->bts_size = 0;
return error;
}
@ -784,6 +799,9 @@ static void ptrace_bts_untrace(struct task_struct *child)
ds_release_bts(child->bts);
child->bts = NULL;
/* We cannot update total_vm and locked_vm since
child's mm is already gone. But we can reclaim the
memory. */
kfree(child->bts_buffer);
child->bts_buffer = NULL;
child->bts_size = 0;
@ -792,7 +810,12 @@ static void ptrace_bts_untrace(struct task_struct *child)
static void ptrace_bts_detach(struct task_struct *child)
{
ptrace_bts_untrace(child);
if (unlikely(child->bts)) {
ds_release_bts(child->bts);
child->bts = NULL;
ptrace_bts_free_buffer(child);
}
}
#else
static inline void ptrace_bts_fork(struct task_struct *tsk) {}

2
include/linux/mm.h
View File

@ -1286,5 +1286,7 @@ int vmemmap_populate_basepages(struct page *start_page,
int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
void vmemmap_populate_print_last(void);
extern void *alloc_locked_buffer(size_t size);
extern void free_locked_buffer(void *buffer, size_t size);
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */

45
mm/mlock.c
View File

@ -667,3 +667,48 @@ void user_shm_unlock(size_t size, struct user_struct *user)
spin_unlock(&shmlock_user_lock);
free_uid(user);
}
void *alloc_locked_buffer(size_t size)
{
unsigned long rlim, vm, pgsz;
void *buffer = NULL;
pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
down_write(&current->mm->mmap_sem);
rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
vm = current->mm->total_vm + pgsz;
if (rlim < vm)
goto out;
rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
vm = current->mm->locked_vm + pgsz;
if (rlim < vm)
goto out;
buffer = kzalloc(size, GFP_KERNEL);
if (!buffer)
goto out;
current->mm->total_vm += pgsz;
current->mm->locked_vm += pgsz;
out:
up_write(&current->mm->mmap_sem);
return buffer;
}
void free_locked_buffer(void *buffer, size_t size)
{
unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
down_write(&current->mm->mmap_sem);
current->mm->total_vm -= pgsz;
current->mm->locked_vm -= pgsz;
up_write(&current->mm->mmap_sem);
kfree(buffer);
}