[XFS] Stack footprint reduction for xfs_swapext (used from xfs_fsr)

[linux-2.6-block.git] / include / linux / sched.h

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 292cb57ce38ff59f396b04aae64fcb4f88b3f290..03b68a7b4b82ae7c775a375f1fe3aa0b6a9909ec 100644 (file)
--- 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;
 
@@ -906,7 +940,7 @@ extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
 #else
 static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)
 {
-       if (!cpus_intersects(new_mask, cpu_online_map))
+       if (!cpu_isset(0, new_mask))
                return -EINVAL;
        return 0;
 }
@@ -1050,6 +1084,11 @@ extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned lon
 #define SEND_SIG_PRIV  ((struct siginfo *) 1)
 #define SEND_SIG_FORCED        ((struct siginfo *) 2)
 
+static inline int is_si_special(const struct siginfo *info)
+{
+       return info <= SEND_SIG_FORCED;
+}
+
 /* True if we are on the alternate signal stack.  */
 
 static inline int on_sig_stack(unsigned long sp)
@@ -1177,7 +1216,7 @@ extern void unhash_process(struct task_struct *p);
 /*
  * Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring
  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
- * pins the final release of task.io_context.
+ * pins the final release of task.io_context.  Also protects ->cpuset.
  *
  * Nests both inside and outside of read_lock(&tasklist_lock).
  * It must not be nested with write_lock_irq(&tasklist_lock),