diff options
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 79 |
1 files changed, 29 insertions, 50 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 6bf981e13c4..4410ac6a55f 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1033,8 +1033,10 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk, need_loop = task_has_mempolicy(tsk) || !nodes_intersects(*newmems, tsk->mems_allowed); - if (need_loop) + if (need_loop) { + local_irq_disable(); write_seqcount_begin(&tsk->mems_allowed_seq); + } nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems); mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1); @@ -1042,8 +1044,10 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk, mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP2); tsk->mems_allowed = *newmems; - if (need_loop) + if (need_loop) { write_seqcount_end(&tsk->mems_allowed_seq); + local_irq_enable(); + } task_unlock(tsk); } @@ -1727,66 +1731,41 @@ out_unlock: * used, list of ranges of sequential numbers, is variable length, * and since these maps can change value dynamically, one could read * gibberish by doing partial reads while a list was changing. - * A single large read to a buffer that crosses a page boundary is - * ok, because the result being copied to user land is not recomputed - * across a page fault. */ - -static size_t cpuset_sprintf_cpulist(char *page, struct cpuset *cs) +static int cpuset_common_seq_show(struct seq_file *sf, void *v) { - size_t count; - - mutex_lock(&callback_mutex); - count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed); - mutex_unlock(&callback_mutex); + struct cpuset *cs = css_cs(seq_css(sf)); + cpuset_filetype_t type = seq_cft(sf)->private; + ssize_t count; + char *buf, *s; + int ret = 0; - return count; -} - -static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs) -{ - size_t count; + count = seq_get_buf(sf, &buf); + s = buf; mutex_lock(&callback_mutex); - count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed); - mutex_unlock(&callback_mutex); - - return count; -} - -static ssize_t cpuset_common_file_read(struct cgroup_subsys_state *css, - struct cftype *cft, struct file *file, - char __user *buf, size_t nbytes, - loff_t *ppos) -{ - struct cpuset *cs = css_cs(css); - cpuset_filetype_t type = cft->private; - char *page; - ssize_t retval = 0; - char *s; - - if (!(page = (char *)__get_free_page(GFP_TEMPORARY))) - return -ENOMEM; - - s = page; switch (type) { case FILE_CPULIST: - s += cpuset_sprintf_cpulist(s, cs); + s += cpulist_scnprintf(s, count, cs->cpus_allowed); break; case FILE_MEMLIST: - s += cpuset_sprintf_memlist(s, cs); + s += nodelist_scnprintf(s, count, cs->mems_allowed); break; default: - retval = -EINVAL; - goto out; + ret = -EINVAL; + goto out_unlock; } - *s++ = '\n'; - retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page); -out: - free_page((unsigned long)page); - return retval; + if (s < buf + count - 1) { + *s++ = '\n'; + seq_commit(sf, s - buf); + } else { + seq_commit(sf, -1); + } +out_unlock: + mutex_unlock(&callback_mutex); + return ret; } static u64 cpuset_read_u64(struct cgroup_subsys_state *css, struct cftype *cft) @@ -1843,7 +1822,7 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft) static struct cftype files[] = { { .name = "cpus", - .read = cpuset_common_file_read, + .seq_show = cpuset_common_seq_show, .write_string = cpuset_write_resmask, .max_write_len = (100U + 6 * NR_CPUS), .private = FILE_CPULIST, @@ -1851,7 +1830,7 @@ static struct cftype files[] = { { .name = "mems", - .read = cpuset_common_file_read, + .seq_show = cpuset_common_seq_show, .write_string = cpuset_write_resmask, .max_write_len = (100U + 6 * MAX_NUMNODES), .private = FILE_MEMLIST, |