1 files changed, 29 insertions, 13 deletions

diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c
index 8aa56736cde3..969365c0771b 100644
--- a/arch/x86_64/kernel/mce.c
+++ b/arch/x86_64/kernel/mce.c
@@ -17,6 +17,7 @@
 #include <linux/fs.h>
 #include <linux/cpu.h>
 #include <linux/percpu.h>
+#include <linux/ctype.h>
 #include <asm/processor.h> 
 #include <asm/msr.h>
 #include <asm/mce.h>
@@ -56,15 +57,19 @@ void mce_log(struct mce *mce)
         smp_wmb();
         for (;;) {
                 entry = rcu_dereference(mcelog.next);
-                /* When the buffer fills up discard new entries. Assume 
-                   that the earlier errors are the more interesting. */
-                if (entry >= MCE_LOG_LEN) {
-                        set_bit(MCE_OVERFLOW, &mcelog.flags);
-                        return;
+                for (;;) {
+                        /* When the buffer fills up discard new entries. Assume
+                           that the earlier errors are the more interesting. */
+                        if (entry >= MCE_LOG_LEN) {
+                                set_bit(MCE_OVERFLOW, &mcelog.flags);
+                                return;
+                        }
+                        /* Old left over entry. Skip. */
+                        if (mcelog.entry[entry].finished) {
+                                entry++;
+                                continue;
+                        }
                 }
-                /* Old left over entry. Skip. */
-                if (mcelog.entry[entry].finished)
-                        continue;
                 smp_rmb();
                 next = entry + 1;
                 if (cmpxchg(&mcelog.next, entry, next) == entry)
@@ -404,9 +409,15 @@ static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff
         }
 
         err = 0;
-        for (i = 0; i < next; i++) {
-                if (!mcelog.entry[i].finished)
-                        continue;
+        for (i = 0; i < next; i++) {            
+                unsigned long start = jiffies;
+                while (!mcelog.entry[i].finished) {
+                        if (!time_before(jiffies, start + 2)) {
+                                memset(mcelog.entry + i,0, sizeof(struct mce));
+                                continue;
+                        }
+                        cpu_relax();
+                }
                 smp_rmb();
                 err |= copy_to_user(buf, mcelog.entry + i, sizeof(struct mce));
                 buf += sizeof(struct mce); 
@@ -479,6 +490,7 @@ static int __init mcheck_disable(char *str)
 
 /* mce=off disables machine check. Note you can reenable it later
    using sysfs.
+   mce=TOLERANCELEVEL (number, see above)
    mce=bootlog Log MCEs from before booting. Disabled by default to work
    around buggy BIOS that leave bogus MCEs.  */
 static int __init mcheck_enable(char *str)
@@ -489,6 +501,8 @@ static int __init mcheck_enable(char *str)
                 mce_dont_init = 1;
         else if (!strcmp(str, "bootlog"))
                 mce_bootlog = 1;
+        else if (isdigit(str[0]))
+                get_option(&str, &tolerant);
         else
                 printk("mce= argument %s ignored. Please use /sys", str); 
         return 0;
@@ -501,10 +515,12 @@ __setup("mce", mcheck_enable);
  * Sysfs support
  */ 
 
-/* On resume clear all MCE state. Don't want to see leftovers from the BIOS. */
+/* On resume clear all MCE state. Don't want to see leftovers from the BIOS.
+   Only one CPU is active at this time, the others get readded later using
+   CPU hotplug. */
 static int mce_resume(struct sys_device *dev)
 {
-        on_each_cpu(mce_init, NULL, 1, 1);
+        mce_init(NULL);
         return 0;
 }