x86/mce: Stop mce_reign() from re-computing severity for every CPU

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  20d51a426f ("x86/mce: Reuse one of the u16 padding fields in 'struct mce'")

a field was added to "struct mce" to save the computed error severity.

Make use of this in mce_reign() to avoid re-computing the severity
for every CPU.

In the case where the machine panics, one call to mce_severity() is
still needed in order to provide the correct message giving the reason
for the panic.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200908175519.14223-2-tony.luck@intel.com
This commit is contained in:
Tony Luck 2020-09-08 10:55:12 -07:00 committed by Borislav Petkov
parent e2def7d49d
commit 13c877f4b4

View file

@ -920,7 +920,6 @@ static void mce_reign(void)
struct mce *m = NULL; struct mce *m = NULL;
int global_worst = 0; int global_worst = 0;
char *msg = NULL; char *msg = NULL;
char *nmsg = NULL;
/* /*
* This CPU is the Monarch and the other CPUs have run * This CPU is the Monarch and the other CPUs have run
@ -928,12 +927,10 @@ static void mce_reign(void)
* Grade the severity of the errors of all the CPUs. * Grade the severity of the errors of all the CPUs.
*/ */
for_each_possible_cpu(cpu) { for_each_possible_cpu(cpu) {
int severity = mce_severity(&per_cpu(mces_seen, cpu), struct mce *mtmp = &per_cpu(mces_seen, cpu);
mca_cfg.tolerant,
&nmsg, true); if (mtmp->severity > global_worst) {
if (severity > global_worst) { global_worst = mtmp->severity;
msg = nmsg;
global_worst = severity;
m = &per_cpu(mces_seen, cpu); m = &per_cpu(mces_seen, cpu);
} }
} }
@ -943,8 +940,11 @@ static void mce_reign(void)
* This dumps all the mces in the log buffer and stops the * This dumps all the mces in the log buffer and stops the
* other CPUs. * other CPUs.
*/ */
if (m && global_worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) if (m && global_worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) {
/* call mce_severity() to get "msg" for panic */
mce_severity(m, mca_cfg.tolerant, &msg, true);
mce_panic("Fatal machine check", m, msg); mce_panic("Fatal machine check", m, msg);
}
/* /*
* For UC somewhere we let the CPU who detects it handle it. * For UC somewhere we let the CPU who detects it handle it.