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s390/cpum_sf: Add raw data sampling to support the diagnostic-sampling function 

Also support the diagnostic-sampling function in addition to the basic-sampling
function.  Diagnostic-sampling data entries contain hardware model specific
sampling data and additional programs are required to analyze the data.

To deliver diagnostic-sampling, as well, as basis-sampling data entries to user
space, introduce support for sampling "raw data".  If this particular perf
sampling type (PERF_SAMPLE_RAW) is used, sampling data entries are copied
to user space.  External programs can then analyze these data.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Hendrik Brueckner 2013-12-13 11:42:44 +01:00 committed by Martin Schwidefsky
parent dd127b3b97
commit 7e75fc3ff4
5 changed files with 377 additions and 96 deletions
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40
arch/s390/include/asm/cpu_mf.h
View File

@ -59,13 +59,15 @@ struct cpumf_ctr_info {
/* QUERY SAMPLING INFORMATION block */
struct hws_qsi_info_block { /* Bit(s) */
unsigned int b0_13:14; /* 0-13: zeros */
unsigned int as:1; /* 14: sampling authorisation control*/
unsigned int b15_21:7; /* 15-21: zeros */
unsigned int es:1; /* 22: sampling enable control */
unsigned int b23_29:7; /* 23-29: zeros */
unsigned int cs:1; /* 30: sampling activation control */
unsigned int:1; /* 31: reserved */
unsigned int bsdes:16; /* 4-5: size of basic sampling entry */
unsigned int as:1; /* 14: basic-sampling authorization */
unsigned int ad:1; /* 15: diag-sampling authorization */
unsigned int b16_21:6; /* 16-21: zeros */
unsigned int es:1; /* 22: basic-sampling enable control */
unsigned int ed:1; /* 23: diag-sampling enable control */
unsigned int b24_29:6; /* 24-29: zeros */
unsigned int cs:1; /* 30: basic-sampling activation control */
unsigned int cd:1; /* 31: diag-sampling activation control */
unsigned int bsdes:16; /* 4-5: size of basic sampling entry */
unsigned int dsdes:16; /* 6-7: size of diagnostic sampling entry */
unsigned long min_sampl_rate; /* 8-15: minimum sampling interval */
unsigned long max_sampl_rate; /* 16-23: maximum sampling interval*/
@ -82,10 +84,11 @@ struct hws_lsctl_request_block {
unsigned int s:1; /* 0: maximum buffer indicator */
unsigned int h:1; /* 1: part. level reserved for VM use*/
unsigned long long b2_53:52;/* 2-53: zeros */
unsigned int es:1; /* 54: sampling enable control */
unsigned int b55_61:7; /* 55-61: - zeros */
unsigned int cs:1; /* 62: sampling activation control */
unsigned int b63:1; /* 63: zero */
unsigned int es:1; /* 54: basic-sampling enable control */
unsigned int ed:1; /* 55: diag-sampling enable control */
unsigned int b56_61:6; /* 56-61: - zeros */
unsigned int cs:1; /* 62: basic-sampling activation control */
unsigned int cd:1; /* 63: diag-sampling activation control */
unsigned long interval; /* 8-15: sampling interval */
unsigned long tear; /* 16-23: TEAR contents */
unsigned long dear; /* 24-31: DEAR contents */
@ -96,8 +99,7 @@ struct hws_lsctl_request_block {
unsigned long rsvrd4; /* reserved */
} __packed;
struct hws_data_entry {
struct hws_basic_entry {
unsigned int def:16; /* 0-15 Data Entry Format */
unsigned int R:4; /* 16-19 reserved */
unsigned int U:4; /* 20-23 Number of unique instruct. */
@ -114,6 +116,18 @@ struct hws_data_entry {
unsigned long long hpp; /* Host Program Parameter */
} __packed;
struct hws_diag_entry {
unsigned int def:16; /* 0-15 Data Entry Format */
unsigned int R:14; /* 16-19 and 20-30 reserved */
unsigned int I:1; /* 31 entry valid or invalid */
u8 data[]; /* Machine-dependent sample data */
} __packed;
struct hws_combined_entry {
struct hws_basic_entry basic; /* Basic-sampling data entry */
struct hws_diag_entry diag; /* Diagnostic-sampling data entry */
} __packed;
struct hws_trailer_entry {
union {
struct {

28
arch/s390/include/asm/perf_event.h
View File

@ -52,15 +52,39 @@ struct perf_sf_sde_regs {
#define PERF_CPUM_CF_MAX_CTR 256
/* Perf PMU definitions for the sampling facility */
#define PERF_CPUM_SF_MAX_CTR 1
#define PERF_EVENT_CPUM_SF 0xB0000UL /* Raw event ID */
#define PERF_CPUM_SF_MAX_CTR 2
#define PERF_EVENT_CPUM_SF 0xB0000UL /* Event: Basic-sampling */
#define PERF_EVENT_CPUM_SF_DIAG 0xBD000UL /* Event: Combined-sampling */
#define PERF_CPUM_SF_BASIC_MODE 0x0001 /* Basic-sampling flag */
#define PERF_CPUM_SF_DIAG_MODE 0x0002 /* Diagnostic-sampling flag */
#define PERF_CPUM_SF_MODE_MASK (PERF_CPUM_SF_BASIC_MODE| \
PERF_CPUM_SF_DIAG_MODE)
#define REG_NONE 0
#define REG_OVERFLOW 1
#define OVERFLOW_REG(hwc) ((hwc)->extra_reg.config)
#define SFB_ALLOC_REG(hwc) ((hwc)->extra_reg.alloc)
#define RAWSAMPLE_REG(hwc) ((hwc)->config)
#define TEAR_REG(hwc) ((hwc)->last_tag)
#define SAMPL_RATE(hwc) ((hwc)->event_base)
#define SAMPL_FLAGS(hwc) ((hwc)->config_base)
#define SAMPL_DIAG_MODE(hwc) (SAMPL_FLAGS(hwc) & PERF_CPUM_SF_DIAG_MODE)
/* Structure for sampling data entries to be passed as perf raw sample data
* to user space. Note that raw sample data must be aligned and, thus, might
* be padded with zeros.
*/
struct sf_raw_sample {
#define SF_RAW_SAMPLE_BASIC PERF_CPUM_SF_BASIC_MODE
#define SF_RAW_SAMPLE_DIAG PERF_CPUM_SF_DIAG_MODE
u64 format;
u32 size; /* Size of sf_raw_sample */
u16 bsdes; /* Basic-sampling data entry size */
u16 dsdes; /* Diagnostic-sampling data entry size */
struct hws_basic_entry basic; /* Basic-sampling data entry */
struct hws_diag_entry diag; /* Diagnostic-sampling data entry */
u8 padding[]; /* Padding to next multiple of 8 */
} __packed;
/* Perf hardware reserve and release functions */
int perf_reserve_sampling(void);

380
arch/s390/kernel/perf_cpum_sf.c
View File

@ -17,6 +17,7 @@
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/moduleparam.h>
#include <asm/cpu_mf.h>
@ -31,8 +32,8 @@
#define CPUM_SF_MIN_SDBT 1
/* Number of sample-data-blocks per sample-data-block-table (SDBT):
* The table contains SDB origin (8 bytes) and one SDBT origin that
* points to the next table.
* A table contains SDB pointers (8 bytes) and one table-link entry
* that points to the origin of the next SDBT.
*/
#define CPUM_SF_SDB_PER_TABLE ((PAGE_SIZE - 8) / 8)
@ -48,8 +49,11 @@ static inline int require_table_link(const void *sdbt)
/* Minimum and maximum sampling buffer sizes:
*
* This number represents the maximum size of the sampling buffer
* taking the number of sample-data-block-tables into account.
* This number represents the maximum size of the sampling buffer taking
* the number of sample-data-block-tables into account. Note that these
* numbers apply to the basic-sampling function only.
* The maximum number of SDBs is increased by CPUM_SF_SDB_DIAG_FACTOR if
* the diagnostic-sampling function is active.
*
* Sampling buffer size Buffer characteristics
* ---------------------------------------------------
@ -63,6 +67,7 @@ static inline int require_table_link(const void *sdbt)
*/
static unsigned long __read_mostly CPUM_SF_MIN_SDB = 15;
static unsigned long __read_mostly CPUM_SF_MAX_SDB = 8176;
static unsigned long __read_mostly CPUM_SF_SDB_DIAG_FACTOR = 1;
struct sf_buffer {
unsigned long *sdbt; /* Sample-data-block-table origin */
@ -290,8 +295,20 @@ static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb)
static void sfb_set_limits(unsigned long min, unsigned long max)
{
struct hws_qsi_info_block si;
CPUM_SF_MIN_SDB = min;
CPUM_SF_MAX_SDB = max;
memset(&si, 0, sizeof(si));
if (!qsi(&si))
CPUM_SF_SDB_DIAG_FACTOR = DIV_ROUND_UP(si.dsdes, si.bsdes);
}
static unsigned long sfb_max_limit(struct hw_perf_event *hwc)
{
return SAMPL_DIAG_MODE(hwc) ? CPUM_SF_MAX_SDB * CPUM_SF_SDB_DIAG_FACTOR
: CPUM_SF_MAX_SDB;
}
static unsigned long sfb_pending_allocs(struct sf_buffer *sfb,
@ -312,8 +329,8 @@ static int sfb_has_pending_allocs(struct sf_buffer *sfb,
static void sfb_account_allocs(unsigned long num, struct hw_perf_event *hwc)
{
/* Limit the number SDBs to not exceed the maximum */
num = min_t(unsigned long, num, CPUM_SF_MAX_SDB - SFB_ALLOC_REG(hwc));
/* Limit the number of SDBs to not exceed the maximum */
num = min_t(unsigned long, num, sfb_max_limit(hwc) - SFB_ALLOC_REG(hwc));
if (num)
SFB_ALLOC_REG(hwc) += num;
}
@ -324,32 +341,89 @@ static void sfb_init_allocs(unsigned long num, struct hw_perf_event *hwc)
sfb_account_allocs(num, hwc);
}
static int allocate_sdbt(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
static size_t event_sample_size(struct hw_perf_event *hwc)
{
unsigned long n_sdb, freq;
unsigned long factor;
struct sf_raw_sample *sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(hwc);
size_t sample_size;
/* The sample size depends on the sampling function: The basic-sampling
* function must be always enabled, diagnostic-sampling function is
* optional.
*/
sample_size = sfr->bsdes;
if (SAMPL_DIAG_MODE(hwc))
sample_size += sfr->dsdes;
return sample_size;
}
static void deallocate_buffers(struct cpu_hw_sf *cpuhw)
{
if (cpuhw->sfb.sdbt)
free_sampling_buffer(&cpuhw->sfb);
}
static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
{
unsigned long n_sdb, freq, factor;
size_t sfr_size, sample_size;
struct sf_raw_sample *sfr;
/* Allocate raw sample buffer
*
* The raw sample buffer is used to temporarily store sampling data
* entries for perf raw sample processing. The buffer size mainly
* depends on the size of diagnostic-sampling data entries which is
* machine-specific. The exact size calculation includes:
* 1. The first 4 bytes of diagnostic-sampling data entries are
* already reflected in the sf_raw_sample structure. Subtract
* these bytes.
* 2. The perf raw sample data must be 8-byte aligned (u64) and
* perf's internal data size must be considered too. So add
* an additional u32 for correct alignment and subtract before
* allocating the buffer.
* 3. Store the raw sample buffer pointer in the perf event
* hardware structure.
*/
sfr_size = ALIGN((sizeof(*sfr) - sizeof(sfr->diag) + cpuhw->qsi.dsdes) +
sizeof(u32), sizeof(u64));
sfr_size -= sizeof(u32);
sfr = kzalloc(sfr_size, GFP_KERNEL);
if (!sfr)
return -ENOMEM;
sfr->size = sfr_size;
sfr->bsdes = cpuhw->qsi.bsdes;
sfr->dsdes = cpuhw->qsi.dsdes;
RAWSAMPLE_REG(hwc) = (unsigned long) sfr;
/* Calculate sampling buffers using 4K pages
*
* 1. Use frequency as input. The samping buffer is designed for
* a complete second. This can be adjusted through the "factor"
* variable.
* 1. Determine the sample data size which depends on the used
* sampling functions, for example, basic-sampling or
* basic-sampling with diagnostic-sampling.
*
* 2. Use the sampling frequency as input. The sampling buffer is
* designed for almost one second. This can be adjusted through
* the "factor" variable.
* In any case, alloc_sampling_buffer() sets the Alert Request
* Control indicator to trigger measurement-alert to harvest
* Control indicator to trigger a measurement-alert to harvest
* sample-data-blocks (sdb).
*
* 2. Compute the number of sample-data-blocks and ensure a minimum
* 3. Compute the number of sample-data-blocks and ensure a minimum
* of CPUM_SF_MIN_SDB. Also ensure the upper limit does not
* exceed CPUM_SF_MAX_SDB. See also the remarks for these
* symbolic constants.
* exceed a "calculated" maximum. The symbolic maximum is
* designed for basic-sampling only and needs to be increased if
* diagnostic-sampling is active.
* See also the remarks for these symbolic constants.
*
* 3. Compute number of pages used for the sample-data-block-table
* and ensure a minimum of CPUM_SF_MIN_SDBT (at minimum one table
* to manage up to 511 sample-data-blocks).
* 4. Compute the number of sample-data-block-tables (SDBT) and
* ensure a minimum of CPUM_SF_MIN_SDBT (one table can manage up
* to 511 SDBs).
*/
sample_size = event_sample_size(hwc);
freq = sample_rate_to_freq(&cpuhw->qsi, SAMPL_RATE(hwc));
factor = 1;
n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / cpuhw->qsi.bsdes));
n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / sample_size));
if (n_sdb < CPUM_SF_MIN_SDB)
n_sdb = CPUM_SF_MIN_SDB;
@ -366,8 +440,10 @@ static int allocate_sdbt(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
return 0;
debug_sprintf_event(sfdbg, 3,
"allocate_sdbt: rate=%lu f=%lu sdb=%lu/%lu cpuhw=%p\n",
SAMPL_RATE(hwc), freq, n_sdb, CPUM_SF_MAX_SDB, cpuhw);
"allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu"
" sample_size=%lu cpuhw=%p\n",
SAMPL_RATE(hwc), freq, n_sdb, sfb_max_limit(hwc),
sample_size, cpuhw);
return alloc_sampling_buffer(&cpuhw->sfb,
sfb_pending_allocs(&cpuhw->sfb, hwc));
@ -509,10 +585,8 @@ static void setup_pmc_cpu(void *flags)
if (err) {
pr_err("Switching off the sampling facility failed "
"with rc=%i\n", err);
} else {
if (cpusf->sfb.sdbt)
free_sampling_buffer(&cpusf->sfb);
}
} else
deallocate_buffers(cpusf);
debug_sprintf_event(sfdbg, 5,
"setup_pmc_cpu: released: cpuhw=%p\n", cpusf);
break;
@ -550,6 +624,10 @@ static int reserve_pmc_hardware(void)
static void hw_perf_event_destroy(struct perf_event *event)
{
/* Free raw sample buffer */
if (RAWSAMPLE_REG(&event->hw))
kfree((void *) RAWSAMPLE_REG(&event->hw));
/* Release PMC if this is the last perf event */
if (!atomic_add_unless(&num_events, -1, 1)) {
mutex_lock(&pmc_reserve_mutex);
@ -569,8 +647,15 @@ static void hw_init_period(struct hw_perf_event *hwc, u64 period)
static void hw_reset_registers(struct hw_perf_event *hwc,
unsigned long *sdbt_origin)
{
struct sf_raw_sample *sfr;
/* (Re)set to first sample-data-block-table */
TEAR_REG(hwc) = (unsigned long) sdbt_origin;
/* (Re)set raw sampling buffer register */
sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(hwc);
memset(&sfr->basic, 0, sizeof(sfr->basic));
memset(&sfr->diag, 0, sfr->dsdes);
}
static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si,
@ -634,6 +719,20 @@ static int __hw_perf_event_init(struct perf_event *event)
goto out;
}
/* Always enable basic sampling */
SAMPL_FLAGS(hwc) = PERF_CPUM_SF_BASIC_MODE;
/* Check if diagnostic sampling is requested. Deny if the required
* sampling authorization is missing.
*/
if (attr->config == PERF_EVENT_CPUM_SF_DIAG) {
if (!si.ad) {
err = -EPERM;
goto out;
}
SAMPL_FLAGS(hwc) |= PERF_CPUM_SF_DIAG_MODE;
}
/* The sampling information (si) contains information about the
* min/max sampling intervals and the CPU speed. So calculate the
* correct sampling interval and avoid the whole period adjust
@ -679,14 +778,14 @@ static int __hw_perf_event_init(struct perf_event *event)
*/
if (cpuhw)
/* Event is pinned to a particular CPU */
err = allocate_sdbt(cpuhw, hwc);
err = allocate_buffers(cpuhw, hwc);
else {
/* Event is not pinned, allocate sampling buffer on
* each online CPU
*/
for_each_online_cpu(cpu) {
cpuhw = &per_cpu(cpu_hw_sf, cpu);
err = allocate_sdbt(cpuhw, hwc);
err = allocate_buffers(cpuhw, hwc);
if (err)
break;
}
@ -705,7 +804,8 @@ static int cpumsf_pmu_event_init(struct perf_event *event)
switch (event->attr.type) {
case PERF_TYPE_RAW:
if (event->attr.config != PERF_EVENT_CPUM_SF)
if ((event->attr.config != PERF_EVENT_CPUM_SF) &&
(event->attr.config != PERF_EVENT_CPUM_SF_DIAG))
return -ENOENT;
break;
case PERF_TYPE_HARDWARE:
@ -786,8 +886,9 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
return;
}
debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i tear=%p dear=%p\n",
cpuhw->lsctl.es, cpuhw->lsctl.cs,
debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i "
"tear=%p dear=%p\n", cpuhw->lsctl.es, cpuhw->lsctl.cs,
cpuhw->lsctl.ed, cpuhw->lsctl.cd,
(void *) cpuhw->lsctl.tear, (void *) cpuhw->lsctl.dear);
}
@ -807,6 +908,7 @@ static void cpumsf_pmu_disable(struct pmu *pmu)
/* Switch off sampling activation control */
inactive = cpuhw->lsctl;
inactive.cs = 0;
inactive.cd = 0;
err = lsctl(&inactive);
if (err) {
@ -867,21 +969,19 @@ static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs,
*
* Return non-zero if an event overflow occurred.
*/
static int perf_push_sample(struct perf_event *event,
struct hws_data_entry *sample)
static int perf_push_sample(struct perf_event *event, struct sf_raw_sample *sfr)
{
int overflow;
struct pt_regs regs;
struct perf_sf_sde_regs *sde_regs;
struct perf_sample_data data;
struct perf_raw_record raw;
/* Skip samples that are invalid or for which the instruction address
* is not predictable. For the latter, the wait-state bit is set.
*/
if (sample->I || sample->W)
return 0;
/* Setup perf sample */
perf_sample_data_init(&data, 0, event->hw.last_period);
raw.size = sfr->size;
raw.data = sfr;
data.raw = &raw;
/* Setup pt_regs to look like an CPU-measurement external interrupt
* using the Program Request Alert code. The regs.int_parm_long
@ -893,14 +993,14 @@ static int perf_push_sample(struct perf_event *event,
regs.int_parm = CPU_MF_INT_SF_PRA;
sde_regs = (struct perf_sf_sde_regs *) &regs.int_parm_long;
regs.psw.addr = sample->ia;
if (sample->T)
regs.psw.addr = sfr->basic.ia;
if (sfr->basic.T)
regs.psw.mask |= PSW_MASK_DAT;
if (sample->W)
if (sfr->basic.W)
regs.psw.mask |= PSW_MASK_WAIT;
if (sample->P)
if (sfr->basic.P)
regs.psw.mask |= PSW_MASK_PSTATE;
switch (sample->AS) {
switch (sfr->basic.AS) {
case 0x0:
regs.psw.mask |= PSW_ASC_PRIMARY;
break;
@ -922,7 +1022,7 @@ static int perf_push_sample(struct perf_event *event,
* purposes too.
* For now, simply use a non-zero value as guest indicator.
*/
if (sample->hpp)
if (sfr->basic.hpp)
sde_regs->in_guest = 1;
overflow = 0;
@ -942,51 +1042,155 @@ static void perf_event_count_update(struct perf_event *event, u64 count)
local64_add(count, &event->count);
}
static int sample_format_is_valid(struct hws_combined_entry *sample,
unsigned int flags)
{
if (likely(flags & PERF_CPUM_SF_BASIC_MODE))
/* Only basic-sampling data entries with data-entry-format
* version of 0x0001 can be processed.
*/
if (sample->basic.def != 0x0001)
return 0;
if (flags & PERF_CPUM_SF_DIAG_MODE)
/* The data-entry-format number of diagnostic-sampling data
* entries can vary. Because diagnostic data is just passed
* through, do only a sanity check on the DEF.
*/
if (sample->diag.def < 0x8001)
return 0;
return 1;
}
static int sample_is_consistent(struct hws_combined_entry *sample,
unsigned long flags)
{
/* This check applies only to basic-sampling data entries of potentially
* combined-sampling data entries. Invalid entries cannot be processed
* by the PMU and, thus, do not deliver an associated
* diagnostic-sampling data entry.
*/
if (unlikely(!(flags & PERF_CPUM_SF_BASIC_MODE)))
return 0;
/*
* Samples are skipped, if they are invalid or for which the
* instruction address is not predictable, i.e., the wait-state bit is
* set.
*/
if (sample->basic.I || sample->basic.W)
return 0;
return 1;
}
static void reset_sample_slot(struct hws_combined_entry *sample,
unsigned long flags)
{
if (likely(flags & PERF_CPUM_SF_BASIC_MODE))
sample->basic.def = 0;
if (flags & PERF_CPUM_SF_DIAG_MODE)
sample->diag.def = 0;
}
static void sfr_store_sample(struct sf_raw_sample *sfr,
struct hws_combined_entry *sample)
{
if (likely(sfr->format & PERF_CPUM_SF_BASIC_MODE))
sfr->basic = sample->basic;
if (sfr->format & PERF_CPUM_SF_DIAG_MODE)
memcpy(&sfr->diag, &sample->diag, sfr->dsdes);
}
static void debug_sample_entry(struct hws_combined_entry *sample,
struct hws_trailer_entry *te,
unsigned long flags)
{
debug_sprintf_event(sfdbg, 4, "hw_collect_samples: Found unknown "
"sampling data entry: te->f=%i basic.def=%04x (%p)"
" diag.def=%04x (%p)\n", te->f,
sample->basic.def, &sample->basic,
(flags & PERF_CPUM_SF_DIAG_MODE)
? sample->diag.def : 0xFFFF,
(flags & PERF_CPUM_SF_DIAG_MODE)
? &sample->diag : NULL);
}
/* hw_collect_samples() - Walk through a sample-data-block and collect samples
* @event: The perf event
* @sdbt: Sample-data-block table
* @overflow: Event overflow counter
*
* Walks through a sample-data-block and collects hardware sample-data that is
* pushed to the perf event subsystem. The overflow reports the number of
* samples that has been discarded due to an event overflow.
* Walks through a sample-data-block and collects sampling data entries that are
* then pushed to the perf event subsystem. Depending on the sampling function,
* there can be either basic-sampling or combined-sampling data entries. A
* combined-sampling data entry consists of a basic- and a diagnostic-sampling
* data entry. The sampling function is determined by the flags in the perf
* event hardware structure. The function always works with a combined-sampling
* data entry but ignores the the diagnostic portion if it is not available.
*
* Note that the implementation focuses on basic-sampling data entries and, if
* such an entry is not valid, the entire combined-sampling data entry is
* ignored.
*
* The overflow variables counts the number of samples that has been discarded
* due to a perf event overflow.
*/
static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
unsigned long long *overflow)
{
struct hws_data_entry *sample;
unsigned long *trailer;
unsigned long flags = SAMPL_FLAGS(&event->hw);
struct hws_combined_entry *sample;
struct hws_trailer_entry *te;
struct sf_raw_sample *sfr;
size_t sample_size;
trailer = trailer_entry_ptr(*sdbt);
sample = (struct hws_data_entry *) *sdbt;
while ((unsigned long *) sample < trailer) {
/* Prepare and initialize raw sample data */
sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(&event->hw);
sfr->format = flags & PERF_CPUM_SF_MODE_MASK;
sample_size = event_sample_size(&event->hw);
te = (struct hws_trailer_entry *) trailer_entry_ptr(*sdbt);
sample = (struct hws_combined_entry *) *sdbt;
while ((unsigned long *) sample < (unsigned long *) te) {
/* Check for an empty sample */
if (!sample->def)
if (!sample->basic.def)
break;
/* Update perf event period */
perf_event_count_update(event, SAMPL_RATE(&event->hw));
/* Check for basic sampling mode */
if (sample->def == 0x0001) {
/* Check sampling data entry */
if (sample_format_is_valid(sample, flags)) {
/* If an event overflow occurred, the PMU is stopped to
* throttle event delivery. Remaining sample data is
* discarded.
*/
if (!*overflow)
*overflow = perf_push_sample(event, sample);
else
if (!*overflow) {
if (sample_is_consistent(sample, flags)) {
/* Deliver sample data to perf */
sfr_store_sample(sfr, sample);
*overflow = perf_push_sample(event, sfr);
}
} else
/* Count discarded samples */
*overflow += 1;
} else
/* Sample slot is not yet written or other record */
debug_sprintf_event(sfdbg, 5, "hw_collect_samples: "
"Unknown sample data entry format:"
" %i\n", sample->def);
} else {
debug_sample_entry(sample, te, flags);
/* Sample slot is not yet written or other record.
*
* This condition can occur if the buffer was reused
* from a combined basic- and diagnostic-sampling.
* If only basic-sampling is then active, entries are
* written into the larger diagnostic entries.
* This is typically the case for sample-data-blocks
* that are not full. Stop processing if the first
* invalid format was detected.
*/
if (!te->f)
break;
}
/* Reset sample slot and advance to next sample */
sample->def = 0;
sample++;
reset_sample_slot(sample, flags);
sample += sample_size;
}
}
@ -1104,6 +1308,8 @@ static void cpumsf_pmu_start(struct perf_event *event, int flags)
perf_pmu_disable(event->pmu);
event->hw.state = 0;
cpuhw->lsctl.cs = 1;
if (SAMPL_DIAG_MODE(&event->hw))
cpuhw->lsctl.cd = 1;
perf_pmu_enable(event->pmu);
}
@ -1119,6 +1325,7 @@ static void cpumsf_pmu_stop(struct perf_event *event, int flags)
perf_pmu_disable(event->pmu);
cpuhw->lsctl.cs = 0;
cpuhw->lsctl.cd = 0;
event->hw.state |= PERF_HES_STOPPED;
if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
@ -1158,11 +1365,13 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags)
/* Ensure sampling functions are in the disabled state. If disabled,
* switch on sampling enable control. */
if (WARN_ON_ONCE(cpuhw->lsctl.es == 1)) {
if (WARN_ON_ONCE(cpuhw->lsctl.es == 1 || cpuhw->lsctl.ed == 1)) {
err = -EAGAIN;
goto out;
}
cpuhw->lsctl.es = 1;
if (SAMPL_DIAG_MODE(&event->hw))
cpuhw->lsctl.ed = 1;
/* Set in_use flag and store event */
event->hw.idx = 0; /* only one sampling event per CPU supported */
@ -1185,6 +1394,7 @@ static void cpumsf_pmu_del(struct perf_event *event, int flags)
cpumsf_pmu_stop(event, PERF_EF_UPDATE);
cpuhw->lsctl.es = 0;
cpuhw->lsctl.ed = 0;
cpuhw->flags &= ~PMU_F_IN_USE;
cpuhw->event = NULL;
@ -1198,9 +1408,11 @@ static int cpumsf_pmu_event_idx(struct perf_event *event)
}
CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC, PERF_EVENT_CPUM_SF);
CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC_DIAG, PERF_EVENT_CPUM_SF_DIAG);
static struct attribute *cpumsf_pmu_events_attr[] = {
CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC),
CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC_DIAG),
NULL,
};
@ -1351,8 +1563,9 @@ static int param_set_sfb_size(const char *val, const struct kernel_param *kp)
return rc;
sfb_set_limits(min, max);
pr_info("Changed sampling buffer settings: min=%lu max=%lu\n",
CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB);
pr_info("The sampling buffer limits have changed to: "
"min=%lu max=%lu (diag=x%lu)\n",
CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB, CPUM_SF_SDB_DIAG_FACTOR);
return 0;
}
@ -1362,13 +1575,38 @@ static struct kernel_param_ops param_ops_sfb_size = {
.get = param_get_sfb_size,
};
#define RS_INIT_FAILURE_QSI 0x0001
#define RS_INIT_FAILURE_BSDES 0x0002
#define RS_INIT_FAILURE_ALRT 0x0003
#define RS_INIT_FAILURE_PERF 0x0004
static void __init pr_cpumsf_err(unsigned int reason)
{
pr_err("Sampling facility support for perf is not available: "
"reason=%04x\n", reason);
}
static int __init init_cpum_sampling_pmu(void)
{
struct hws_qsi_info_block si;
int err;
if (!cpum_sf_avail())
return -ENODEV;
memset(&si, 0, sizeof(si));
if (qsi(&si)) {
pr_cpumsf_err(RS_INIT_FAILURE_QSI);
return -ENODEV;
}
if (si.bsdes != sizeof(struct hws_basic_entry)) {
pr_cpumsf_err(RS_INIT_FAILURE_BSDES);
return -EINVAL;
}
if (si.ad)
sfb_set_limits(CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB);
sfdbg = debug_register(KMSG_COMPONENT, 2, 1, 80);
if (!sfdbg)
pr_err("Registering for s390dbf failed\n");
@ -1376,13 +1614,13 @@ static int __init init_cpum_sampling_pmu(void)
err = register_external_interrupt(0x1407, cpumf_measurement_alert);
if (err) {
pr_err("Failed to register for CPU-measurement alerts\n");
pr_cpumsf_err(RS_INIT_FAILURE_ALRT);
goto out;
}
err = perf_pmu_register(&cpumf_sampling, "cpum_sf", PERF_TYPE_RAW);
if (err) {
pr_err("Failed to register cpum_sf pmu\n");
pr_cpumsf_err(RS_INIT_FAILURE_PERF);
unregister_external_interrupt(0x1407, cpumf_measurement_alert);
goto out;
}

21
arch/s390/kernel/perf_event.c
View File

@ -139,16 +139,21 @@ static void print_debug_sf(void)
int cpu = smp_processor_id();
memset(&si, 0, sizeof(si));
if (qsi(&si)) {
pr_err("CPU[%i]: CPM_SF: qsi failed\n");
if (qsi(&si))
return;
}
pr_info("CPU[%i]: CPM_SF: as=%i es=%i cs=%i bsdes=%i dsdes=%i"
" min=%i max=%i cpu_speed=%i tear=%p dear=%p\n",
cpu, si.as, si.es, si.cs, si.bsdes, si.dsdes,
si.min_sampl_rate, si.max_sampl_rate, si.cpu_speed,
si.tear, si.dear);
pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%i max=%i cpu_speed=%i\n",
cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
si.cpu_speed);
if (si.as)
pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
" bsdes=%i tear=%p dear=%p\n", cpu,
si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
if (si.ad)
pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
" dsdes=%i tear=%p dear=%p\n", cpu,
si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
}
void perf_event_print_debug(void)

4
arch/s390/oprofile/hwsampler.c
View File

@ -799,7 +799,7 @@ static void worker_on_interrupt(unsigned int cpu)
static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
unsigned long *dear)
{
struct hws_data_entry *sample_data_ptr;
struct hws_basic_entry *sample_data_ptr;
unsigned long *trailer;
trailer = trailer_entry_ptr(*sdbt);
@ -809,7 +809,7 @@ static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
trailer = dear;
}
sample_data_ptr = (struct hws_data_entry *)(*sdbt);
sample_data_ptr = (struct hws_basic_entry *)(*sdbt);
while ((unsigned long *)sample_data_ptr < trailer) {
struct pt_regs *regs = NULL;