Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f17c86...
Commit: f17c860760927c2a8e41a021eab3317e4415e962
Parent: a0e902452da16b79d7c9230630ed8a595d14fa85
Author: Rusty Russell <rusty@rustcorp.com.au>
AuthorDate: Tue Nov 25 02:35:11 2008 +1030
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Mon Nov 24 17:51:45 2008 +0100
sched: convert sys_sched_getaffinity() to cpumask_var_t.
Impact: stack usage reduction
Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space in the stack. cpumask_var_t is just a struct cpumask for
!CONFIG_CPUMASK_OFFSTACK.
Some jiggling here to make sure we always exit at the bottom (so we hit
the free_cpumask_var there).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/sched.c | 21 +++++++++++++--------
1 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 67383e7..6deff24 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5499,19 +5499,24 @@ asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
unsigned long __user *user_mask_ptr)
{
int ret;
- cpumask_t mask;
+ cpumask_var_t mask;
- if (len < sizeof(cpumask_t))
+ if (len < cpumask_size())
return -EINVAL;
- ret = sched_getaffinity(pid, &mask);
- if (ret < 0)
- return ret;
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+ return -ENOMEM;
- if (copy_to_user(user_mask_ptr, &mask, sizeof(cpumask_t)))
- return -EFAULT;
+ ret = sched_getaffinity(pid, mask);
+ if (ret == 0) {
+ if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
+ ret = -EFAULT;
+ else
+ ret = cpumask_size();
+ }
+ free_cpumask_var(mask);
- return sizeof(cpumask_t);
+ return ret;
}
/**
--
