diff options
author | Hugh Dickins <hugh@veritas.com> | 2005-10-29 18:16:41 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-29 21:40:42 -0700 |
commit | f412ac08c9861b4791af0145934c22f1458686da (patch) | |
tree | 5e515efa116f3968c2caa75bc691a197199313a8 /include/linux/sched.h | |
parent | 4c21e2f2441dc5fbb957b030333f5a3f2d02dea7 (diff) | |
download | op-kernel-dev-f412ac08c9861b4791af0145934c22f1458686da.zip op-kernel-dev-f412ac08c9861b4791af0145934c22f1458686da.tar.gz |
[PATCH] mm: fix rss and mmlist locking
A couple of oddities were guarded by page_table_lock, no longer properly
guarded when that is split.
The mm_counters of file_rss and anon_rss: make those an atomic_t, or an
atomic64_t if the architecture supports it, in such a case. Definitions by
courtesy of Christoph Lameter: who spent considerable effort on more scalable
ways of counting, but found insufficient benefit in practice.
And adding an mm with swap to the mmlist for swapoff: the list is well-
guarded by its own lock, but the list_empty check now has to be repeated
inside it.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r-- | include/linux/sched.h | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 292cb57..1c30bc3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -249,13 +249,47 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr, extern void arch_unmap_area(struct mm_struct *, unsigned long); extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long); +#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS +/* + * The mm counters are not protected by its page_table_lock, + * so must be incremented atomically. + */ +#ifdef ATOMIC64_INIT +#define set_mm_counter(mm, member, value) atomic64_set(&(mm)->_##member, value) +#define get_mm_counter(mm, member) ((unsigned long)atomic64_read(&(mm)->_##member)) +#define add_mm_counter(mm, member, value) atomic64_add(value, &(mm)->_##member) +#define inc_mm_counter(mm, member) atomic64_inc(&(mm)->_##member) +#define dec_mm_counter(mm, member) atomic64_dec(&(mm)->_##member) +typedef atomic64_t mm_counter_t; +#else /* !ATOMIC64_INIT */ +/* + * The counters wrap back to 0 at 2^32 * PAGE_SIZE, + * that is, at 16TB if using 4kB page size. + */ +#define set_mm_counter(mm, member, value) atomic_set(&(mm)->_##member, value) +#define get_mm_counter(mm, member) ((unsigned long)atomic_read(&(mm)->_##member)) +#define add_mm_counter(mm, member, value) atomic_add(value, &(mm)->_##member) +#define inc_mm_counter(mm, member) atomic_inc(&(mm)->_##member) +#define dec_mm_counter(mm, member) atomic_dec(&(mm)->_##member) +typedef atomic_t mm_counter_t; +#endif /* !ATOMIC64_INIT */ + +#else /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */ +/* + * The mm counters are protected by its page_table_lock, + * so can be incremented directly. + */ #define set_mm_counter(mm, member, value) (mm)->_##member = (value) #define get_mm_counter(mm, member) ((mm)->_##member) #define add_mm_counter(mm, member, value) (mm)->_##member += (value) #define inc_mm_counter(mm, member) (mm)->_##member++ #define dec_mm_counter(mm, member) (mm)->_##member-- -#define get_mm_rss(mm) ((mm)->_file_rss + (mm)->_anon_rss) +typedef unsigned long mm_counter_t; + +#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */ +#define get_mm_rss(mm) \ + (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss)) #define update_hiwater_rss(mm) do { \ unsigned long _rss = get_mm_rss(mm); \ if ((mm)->hiwater_rss < _rss) \ @@ -266,8 +300,6 @@ extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long); (mm)->hiwater_vm = (mm)->total_vm; \ } while (0) -typedef unsigned long mm_counter_t; - struct mm_struct { struct vm_area_struct * mmap; /* list of VMAs */ struct rb_root mm_rb; @@ -291,7 +323,9 @@ struct mm_struct { * by mmlist_lock */ - /* Special counters protected by the page_table_lock */ + /* Special counters, in some configurations protected by the + * page_table_lock, in other configurations by being atomic. + */ mm_counter_t _file_rss; mm_counter_t _anon_rss; |