diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-11-25 02:35:11 +1030 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-24 17:51:45 +0100 |
| commit | f17c860760927c2a8e41a021eab3317e4415e962 (patch) | |
| tree | 6b414506bd3822f0b3475d454a10f16025a5415c /kernel | |
| parent | a0e902452da16b79d7c9230630ed8a595d14fa85 (diff) | |
| download | linux-f17c860760927c2a8e41a021eab3317e4415e962.tar.gz linux-f17c860760927c2a8e41a021eab3317e4415e962.tar.bz2 linux-f17c860760927c2a8e41a021eab3317e4415e962.zip | |
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 67383e7f1ccd..6deff24349b6 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; } /** |