[PATCH v2 1/4] cpuset: Remove unneeded NODEMASK_ALLOC() in cpuset_sprintf_memlist()

From: Li Zefan
Date: Thu Feb 24 2011 - 01:55:18 EST

It's not necessary to copy cpuset->mems_allowed to a buffer
allocated by NODEMASK_ALLOC(). Just pass it to nodelist_scnprintf().

As spotted by Paul, a side effect is we fix a bug that the function
can return -ENOMEM but the caller doesn't expect negative return
value. Therefore change the return value of cpuset_sprintf_cpulist()
and cpuset_sprintf_memlist() from int to size_t.

Acked-by: Paul Menage <menage@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
kernel/cpuset.c | 24 ++++++++----------------
1 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 10f1835..e79650b 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1607,34 +1607,26 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
* across a page fault.

-static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
+static size_t cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
- int ret;
+ size_t count;

- ret = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);
+ count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);

- return ret;
+ return count;

-static int cpuset_sprintf_memlist(char *page, struct cpuset *cs)
+static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs)
- NODEMASK_ALLOC(nodemask_t, mask, GFP_KERNEL);
- int retval;
- if (mask == NULL)
- return -ENOMEM;
+ size_t count;

- *mask = cs->mems_allowed;
+ count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed);

- retval = nodelist_scnprintf(page, PAGE_SIZE, *mask);
- return retval;
+ return count;

static ssize_t cpuset_common_file_read(struct cgroup *cont,
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