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[PATCH] x86_64: Remove excessive stack allocation in MCE code with large NR_CPUS

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Remove excessive stack allocation in MCE code with large NR_CPUS

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andi Kleen 2005-04-16 15:25:10 -07:00 committed by Linus Torvalds
parent 94ad84740f
commit f0de53bbc2
1 changed files with 7 additions and 1 deletions
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8
arch/x86_64/kernel/mce.c
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@ -379,18 +379,23 @@ static void collect_tscs(void *data)
static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off) static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off)
{ {
unsigned long cpu_tsc[NR_CPUS]; unsigned long *cpu_tsc;
static DECLARE_MUTEX(mce_read_sem); static DECLARE_MUTEX(mce_read_sem);
unsigned next; unsigned next;
char __user *buf = ubuf; char __user *buf = ubuf;
int i, err; int i, err;
cpu_tsc = kmalloc(NR_CPUS * sizeof(long), GFP_KERNEL);
if (!cpu_tsc)
return -ENOMEM;
down(&mce_read_sem); down(&mce_read_sem);
next = rcu_dereference(mcelog.next); next = rcu_dereference(mcelog.next);
/* Only supports full reads right now */ /* Only supports full reads right now */
if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) { if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) {
up(&mce_read_sem); up(&mce_read_sem);
kfree(cpu_tsc);
return -EINVAL; return -EINVAL;
} }
@ -421,6 +426,7 @@ static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff
} }
} }
up(&mce_read_sem); up(&mce_read_sem);
kfree(cpu_tsc);
return err ? -EFAULT : buf - ubuf; return err ? -EFAULT : buf - ubuf;
} }