Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86_cache_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 resctrl update from Dave Hansen:
"Reduce redundant counter reads with resctrl refactoring"
* tag 'x86_cache_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Avoid redundant counter read in __mon_event_count()
+19
-24
+19
-24
arch/x86/kernel/cpu/resctrl/monitor.c
+19
-24
arch/x86/kernel/cpu/resctrl/monitor.c
···
383
383
list_add_tail(&entry->list, &rmid_free_lru);
384
384
}
385
385
386
+
static struct mbm_state *get_mbm_state(struct rdt_domain *d, u32 rmid,
387
+
enum resctrl_event_id evtid)
388
+
{
389
+
switch (evtid) {
390
+
case QOS_L3_MBM_TOTAL_EVENT_ID:
391
+
return &d->mbm_total[rmid];
392
+
case QOS_L3_MBM_LOCAL_EVENT_ID:
393
+
return &d->mbm_local[rmid];
394
+
default:
395
+
return NULL;
396
+
}
397
+
}
398
+
386
399
static int __mon_event_count(u32 rmid, struct rmid_read *rr)
387
400
{
388
401
struct mbm_state *m;
389
402
u64 tval = 0;
390
403
391
-
if (rr->first)
404
+
if (rr->first) {
392
405
resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);
406
+
m = get_mbm_state(rr->d, rmid, rr->evtid);
407
+
if (m)
408
+
memset(m, 0, sizeof(struct mbm_state));
409
+
return 0;
410
+
}
393
411
394
412
rr->err = resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval);
395
413
if (rr->err)
396
414
return rr->err;
397
-
398
-
switch (rr->evtid) {
399
-
case QOS_L3_OCCUP_EVENT_ID:
400
-
rr->val += tval;
401
-
return 0;
402
-
case QOS_L3_MBM_TOTAL_EVENT_ID:
403
-
m = &rr->d->mbm_total[rmid];
404
-
break;
405
-
case QOS_L3_MBM_LOCAL_EVENT_ID:
406
-
m = &rr->d->mbm_local[rmid];
407
-
break;
408
-
default:
409
-
/*
410
-
* Code would never reach here because an invalid
411
-
* event id would fail in resctrl_arch_rmid_read().
412
-
*/
413
-
return -EINVAL;
414
-
}
415
-
416
-
if (rr->first) {
417
-
memset(m, 0, sizeof(struct mbm_state));
418
-
return 0;
419
-
}
420
415
421
416
rr->val += tval;
422
417