iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

s390/pai_ext: Enable per-task and system-wide sampling event

Browse Source 
The PMU for PAI NNPA counters enforces the following restriction:

 - No per-task context for PAI sampling event NNPA_ALL
 - No multiple system-wide PAI sampling event NNPA_ALL

Both restrictions are removed. One or more per-task sampling events
are supported. Also one or more system-wide sampling events are
supported.

Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Thomas Richter 2024-04-15 16:41:23 +02:00 committed by Alexander Gordeev
parent 3f9ff4c5a0
commit 582cc1b28e
3 changed files with 41 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/s390/include/asm/pai.h
View File

@ -75,12 +75,8 @@ static __always_inline void pai_kernel_exit(struct pt_regs *regs)
WRITE_ONCE(S390_lowcore.ccd, S390_lowcore.ccd & ~PAI_CRYPTO_KERNEL_OFFSET);
}
enum paievt_mode {
PAI_MODE_NONE,
PAI_MODE_SAMPLING,
PAI_MODE_COUNTING,
};
#define PAI_SAVE_AREA(x) ((x)->hw.event_base)
#define PAI_CPU_MASK(x) ((x)->hw.addr_filters)
#define PAI_SWLIST(x) (&(x)->hw.tp_list)
#endif

2
arch/s390/kernel/perf_pai_crypto.c
View File

@ -24,8 +24,6 @@ static debug_info_t *cfm_dbg;
static unsigned int paicrypt_cnt; /* Size of the mapped counter sets */
/* extracted with QPACI instruction */
#define PAI_SWLIST(x) (&(x)->hw.tp_list)
DEFINE_STATIC_KEY_FALSE(pai_key);
struct pai_userdata {

75
arch/s390/kernel/perf_pai_ext.c
View File

@ -47,11 +47,11 @@ struct paiext_cb { /* PAI extension 1 control block */
struct paiext_map {
unsigned long *area; /* Area for CPU to store counters */
struct pai_userdata *save; /* Area to store non-zero counters */
enum paievt_mode mode; /* Type of event */
unsigned int active_events; /* # of PAI Extension users */
refcount_t refcnt;
struct perf_event *event; /* Perf event for sampling */
struct paiext_cb *paiext_cb; /* PAI extension control block area */
struct list_head syswide_list; /* List system-wide sampling events */
};
struct paiext_mapptr {
@ -70,6 +70,8 @@ static void paiext_root_free(void)
free_percpu(paiext_root.mapptr);
paiext_root.mapptr = NULL;
}
debug_sprintf_event(paiext_dbg, 5, "%s root.refcount %d\n", __func__,
refcount_read(&paiext_root.refcnt));
}
/* On initialization of first event also allocate per CPU data dynamically.
@ -121,8 +123,6 @@ static void paiext_event_destroy_cpu(struct perf_event *event, int cpu)
struct paiext_map *cpump = mp->mapptr;
mutex_lock(&paiext_reserve_mutex);
if (event->attr.sample_period)
cpump->mode &= ~PAI_MODE_SAMPLING;
if (refcount_dec_and_test(&cpump->refcnt)) /* Last reference gone */
paiext_free(mp);
paiext_root_free();
@ -161,7 +161,7 @@ static void paiext_event_destroy(struct perf_event *event)
*
* Allocate the memory for the event.
*/
static int paiext_alloc_cpu(struct perf_event_attr *a, int cpu)
static int paiext_alloc_cpu(struct perf_event *event, int cpu)
{
struct paiext_mapptr *mp;
struct paiext_map *cpump;
@ -200,21 +200,12 @@ static int paiext_alloc_cpu(struct perf_event_attr *a, int cpu)
paiext_free(mp);
goto undo;
}
INIT_LIST_HEAD(&cpump->syswide_list);
refcount_set(&cpump->refcnt, 1);
rc = 0;
} else {
/* Multiple invocation, check what is active.
* Supported are multiple counter events and only one sampling
* event concurrently at any one time.
*/
if (a->sample_period && (cpump->mode & PAI_MODE_SAMPLING)) {
rc = -EBUSY;
goto undo;
}
refcount_inc(&cpump->refcnt);
}
if (a->sample_period)
cpump->mode |= PAI_MODE_SAMPLING;
rc = 0;
undo:
if (rc) {
@ -240,7 +231,7 @@ static int paiext_alloc(struct perf_event *event)
goto out;
for_each_online_cpu(cpu) {
rc = paiext_alloc_cpu(&event->attr, cpu);
rc = paiext_alloc_cpu(event, cpu);
if (rc) {
for_each_cpu(cpu, maskptr)
paiext_event_destroy_cpu(event, cpu);
@ -259,8 +250,6 @@ static int paiext_alloc(struct perf_event *event)
PAI_CPU_MASK(event) = maskptr;
rc = 0;
out:
debug_sprintf_event(paiext_dbg, 5, "%s cpu %u rc %d\n", __func__,
cpu, rc);
return rc;
}
@ -293,10 +282,6 @@ static int paiext_event_init(struct perf_event *event)
rc = paiext_event_valid(event);
if (rc)
return rc;
/* Allow only CPU wide operation for sampling */
if (a->sample_period &&
((event->attach_state & PERF_ATTACH_TASK) || event->cpu == -1))
return -ENOENT;
/* Allow only event NNPA_ALL for sampling. */
if (a->sample_period && a->config != PAI_NNPA_BASE)
return -EINVAL;
@ -311,7 +296,7 @@ static int paiext_event_init(struct perf_event *event)
}
if (event->cpu >= 0)
rc = paiext_alloc_cpu(a, event->cpu);
rc = paiext_alloc_cpu(event, event->cpu);
else
rc = paiext_alloc(event);
if (rc) {
@ -385,10 +370,15 @@ static void paiext_start(struct perf_event *event, int flags)
sum = paiext_getall(event); /* Get current value */
local64_set(&event->hw.prev_count, sum);
} else { /* Sampling */
cpump->event = event;
memcpy((void *)PAI_SAVE_AREA(event), cpump->area,
PAIE1_CTRBLOCK_SZ);
perf_sched_cb_inc(event->pmu);
/* Enable context switch callback for system-wide sampling */
if (!(event->attach_state & PERF_ATTACH_TASK)) {
list_add_tail(PAI_SWLIST(event), &cpump->syswide_list);
perf_sched_cb_inc(event->pmu);
} else {
cpump->event = event;
}
}
}
@ -410,6 +400,7 @@ static int paiext_add(struct perf_event *event, int flags)
return 0;
}
static void paiext_have_sample(struct perf_event *, struct paiext_map *);
static void paiext_stop(struct perf_event *event, int flags)
{
struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr);
@ -418,8 +409,13 @@ static void paiext_stop(struct perf_event *event, int flags)
if (!event->attr.sample_period) { /* Counting */
paiext_read(event);
} else { /* Sampling */
perf_sched_cb_dec(event->pmu);
cpump->event = NULL;
if (!(event->attach_state & PERF_ATTACH_TASK)) {
list_del(PAI_SWLIST(event));
perf_sched_cb_dec(event->pmu);
} else {
paiext_have_sample(event, cpump);
cpump->event = NULL;
}
}
event->hw.state = PERF_HES_STOPPED;
}
@ -519,21 +515,28 @@ static int paiext_push_sample(size_t rawsize, struct paiext_map *cpump,
}
/* Check if there is data to be saved on schedule out of a task. */
static int paiext_have_sample(void)
static void paiext_have_sample(struct perf_event *event,
struct paiext_map *cpump)
{
struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr);
struct paiext_map *cpump = mp->mapptr;
struct perf_event *event = cpump->event;
size_t rawsize;
int rc = 0;
if (!event)
return 0;
return;
rawsize = paiext_copy(cpump->save, cpump->area,
(unsigned long *)PAI_SAVE_AREA(event));
if (rawsize) /* Incremented counters */
rc = paiext_push_sample(rawsize, cpump, event);
return rc;
paiext_push_sample(rawsize, cpump, event);
}
/* Check if there is data to be saved on schedule out of a task. */
static void paiext_have_samples(void)
{
struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr);
struct paiext_map *cpump = mp->mapptr;
struct perf_event *event;
list_for_each_entry(event, &cpump->syswide_list, hw.tp_list)
paiext_have_sample(event, cpump);
}
/* Called on schedule-in and schedule-out. No access to event structure,
@ -545,7 +548,7 @@ static void paiext_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched
* results on schedule_out and if page was dirty, save old values.
*/
if (!sched_in)
paiext_have_sample();
paiext_have_samples();
}
/* Attribute definitions for pai extension1 interface. As with other CPU