Revision 9c29bcd189f4ab1644b7125713602532d0aefdb7 authored by Eric Dumazet on 21 September 2018, 22:27:48 UTC, committed by David S. Miller on 24 September 2018, 04:55:25 UTC
As diagnosed by Song Liu, ndo_poll_controller() can be very dangerous on loaded hosts, since the cpu calling ndo_poll_controller() might steal all NAPI contexts (for all RX/TX queues of the NIC). This capture can last for unlimited amount of time, since one cpu is generally not able to drain all the queues under load. mlx5 uses NAPI for TX completions, so we better let core networking stack call the napi->poll() to avoid the capture. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent a24b66c
mem-events.c
// SPDX-License-Identifier: GPL-2.0
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <api/fs/fs.h>
#include <linux/kernel.h>
#include "mem-events.h"
#include "debug.h"
#include "symbol.h"
#include "sort.h"
unsigned int perf_mem_events__loads_ldlat = 30;
#define E(t, n, s) { .tag = t, .name = n, .sysfs_name = s }
struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
E("ldlat-loads", "cpu/mem-loads,ldlat=%u/P", "mem-loads"),
E("ldlat-stores", "cpu/mem-stores/P", "mem-stores"),
};
#undef E
#undef E
static char mem_loads_name[100];
static bool mem_loads_name__init;
char *perf_mem_events__name(int i)
{
if (i == PERF_MEM_EVENTS__LOAD) {
if (!mem_loads_name__init) {
mem_loads_name__init = true;
scnprintf(mem_loads_name, sizeof(mem_loads_name),
perf_mem_events[i].name,
perf_mem_events__loads_ldlat);
}
return mem_loads_name;
}
return (char *)perf_mem_events[i].name;
}
int perf_mem_events__parse(const char *str)
{
char *tok, *saveptr = NULL;
bool found = false;
char *buf;
int j;
/* We need buffer that we know we can write to. */
buf = malloc(strlen(str) + 1);
if (!buf)
return -ENOMEM;
strcpy(buf, str);
tok = strtok_r((char *)buf, ",", &saveptr);
while (tok) {
for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
struct perf_mem_event *e = &perf_mem_events[j];
if (strstr(e->tag, tok))
e->record = found = true;
}
tok = strtok_r(NULL, ",", &saveptr);
}
free(buf);
if (found)
return 0;
pr_err("failed: event '%s' not found, use '-e list' to get list of available events\n", str);
return -1;
}
int perf_mem_events__init(void)
{
const char *mnt = sysfs__mount();
bool found = false;
int j;
if (!mnt)
return -ENOENT;
for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
char path[PATH_MAX];
struct perf_mem_event *e = &perf_mem_events[j];
struct stat st;
scnprintf(path, PATH_MAX, "%s/devices/cpu/events/%s",
mnt, e->sysfs_name);
if (!stat(path, &st))
e->supported = found = true;
}
return found ? 0 : -ENOENT;
}
static const char * const tlb_access[] = {
"N/A",
"HIT",
"MISS",
"L1",
"L2",
"Walker",
"Fault",
};
int perf_mem__tlb_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
size_t l = 0, i;
u64 m = PERF_MEM_TLB_NA;
u64 hit, miss;
sz -= 1; /* -1 for null termination */
out[0] = '\0';
if (mem_info)
m = mem_info->data_src.mem_dtlb;
hit = m & PERF_MEM_TLB_HIT;
miss = m & PERF_MEM_TLB_MISS;
/* already taken care of */
m &= ~(PERF_MEM_TLB_HIT|PERF_MEM_TLB_MISS);
for (i = 0; m && i < ARRAY_SIZE(tlb_access); i++, m >>= 1) {
if (!(m & 0x1))
continue;
if (l) {
strcat(out, " or ");
l += 4;
}
l += scnprintf(out + l, sz - l, tlb_access[i]);
}
if (*out == '\0')
l += scnprintf(out, sz - l, "N/A");
if (hit)
l += scnprintf(out + l, sz - l, " hit");
if (miss)
l += scnprintf(out + l, sz - l, " miss");
return l;
}
static const char * const mem_lvl[] = {
"N/A",
"HIT",
"MISS",
"L1",
"LFB",
"L2",
"L3",
"Local RAM",
"Remote RAM (1 hop)",
"Remote RAM (2 hops)",
"Remote Cache (1 hop)",
"Remote Cache (2 hops)",
"I/O",
"Uncached",
};
static const char * const mem_lvlnum[] = {
[PERF_MEM_LVLNUM_ANY_CACHE] = "Any cache",
[PERF_MEM_LVLNUM_LFB] = "LFB",
[PERF_MEM_LVLNUM_RAM] = "RAM",
[PERF_MEM_LVLNUM_PMEM] = "PMEM",
[PERF_MEM_LVLNUM_NA] = "N/A",
};
int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
size_t i, l = 0;
u64 m = PERF_MEM_LVL_NA;
u64 hit, miss;
int printed;
if (mem_info)
m = mem_info->data_src.mem_lvl;
sz -= 1; /* -1 for null termination */
out[0] = '\0';
hit = m & PERF_MEM_LVL_HIT;
miss = m & PERF_MEM_LVL_MISS;
/* already taken care of */
m &= ~(PERF_MEM_LVL_HIT|PERF_MEM_LVL_MISS);
if (mem_info && mem_info->data_src.mem_remote) {
strcat(out, "Remote ");
l += 7;
}
printed = 0;
for (i = 0; m && i < ARRAY_SIZE(mem_lvl); i++, m >>= 1) {
if (!(m & 0x1))
continue;
if (printed++) {
strcat(out, " or ");
l += 4;
}
l += scnprintf(out + l, sz - l, mem_lvl[i]);
}
if (mem_info && mem_info->data_src.mem_lvl_num) {
int lvl = mem_info->data_src.mem_lvl_num;
if (printed++) {
strcat(out, " or ");
l += 4;
}
if (mem_lvlnum[lvl])
l += scnprintf(out + l, sz - l, mem_lvlnum[lvl]);
else
l += scnprintf(out + l, sz - l, "L%d", lvl);
}
if (l == 0)
l += scnprintf(out + l, sz - l, "N/A");
if (hit)
l += scnprintf(out + l, sz - l, " hit");
if (miss)
l += scnprintf(out + l, sz - l, " miss");
return l;
}
static const char * const snoop_access[] = {
"N/A",
"None",
"Hit",
"Miss",
"HitM",
};
int perf_mem__snp_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
size_t i, l = 0;
u64 m = PERF_MEM_SNOOP_NA;
sz -= 1; /* -1 for null termination */
out[0] = '\0';
if (mem_info)
m = mem_info->data_src.mem_snoop;
for (i = 0; m && i < ARRAY_SIZE(snoop_access); i++, m >>= 1) {
if (!(m & 0x1))
continue;
if (l) {
strcat(out, " or ");
l += 4;
}
l += scnprintf(out + l, sz - l, snoop_access[i]);
}
if (mem_info &&
(mem_info->data_src.mem_snoopx & PERF_MEM_SNOOPX_FWD)) {
if (l) {
strcat(out, " or ");
l += 4;
}
l += scnprintf(out + l, sz - l, "Fwd");
}
if (*out == '\0')
l += scnprintf(out, sz - l, "N/A");
return l;
}
int perf_mem__lck_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
u64 mask = PERF_MEM_LOCK_NA;
int l;
if (mem_info)
mask = mem_info->data_src.mem_lock;
if (mask & PERF_MEM_LOCK_NA)
l = scnprintf(out, sz, "N/A");
else if (mask & PERF_MEM_LOCK_LOCKED)
l = scnprintf(out, sz, "Yes");
else
l = scnprintf(out, sz, "No");
return l;
}
int perf_script__meminfo_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
int i = 0;
i += perf_mem__lvl_scnprintf(out, sz, mem_info);
i += scnprintf(out + i, sz - i, "|SNP ");
i += perf_mem__snp_scnprintf(out + i, sz - i, mem_info);
i += scnprintf(out + i, sz - i, "|TLB ");
i += perf_mem__tlb_scnprintf(out + i, sz - i, mem_info);
i += scnprintf(out + i, sz - i, "|LCK ");
i += perf_mem__lck_scnprintf(out + i, sz - i, mem_info);
return i;
}
int c2c_decode_stats(struct c2c_stats *stats, struct mem_info *mi)
{
union perf_mem_data_src *data_src = &mi->data_src;
u64 daddr = mi->daddr.addr;
u64 op = data_src->mem_op;
u64 lvl = data_src->mem_lvl;
u64 snoop = data_src->mem_snoop;
u64 lock = data_src->mem_lock;
/*
* Skylake might report unknown remote level via this
* bit, consider it when evaluating remote HITMs.
*/
bool mrem = data_src->mem_remote;
int err = 0;
#define HITM_INC(__f) \
do { \
stats->__f++; \
stats->tot_hitm++; \
} while (0)
#define P(a, b) PERF_MEM_##a##_##b
stats->nr_entries++;
if (lock & P(LOCK, LOCKED)) stats->locks++;
if (op & P(OP, LOAD)) {
/* load */
stats->load++;
if (!daddr) {
stats->ld_noadrs++;
return -1;
}
if (lvl & P(LVL, HIT)) {
if (lvl & P(LVL, UNC)) stats->ld_uncache++;
if (lvl & P(LVL, IO)) stats->ld_io++;
if (lvl & P(LVL, LFB)) stats->ld_fbhit++;
if (lvl & P(LVL, L1 )) stats->ld_l1hit++;
if (lvl & P(LVL, L2 )) stats->ld_l2hit++;
if (lvl & P(LVL, L3 )) {
if (snoop & P(SNOOP, HITM))
HITM_INC(lcl_hitm);
else
stats->ld_llchit++;
}
if (lvl & P(LVL, LOC_RAM)) {
stats->lcl_dram++;
if (snoop & P(SNOOP, HIT))
stats->ld_shared++;
else
stats->ld_excl++;
}
if ((lvl & P(LVL, REM_RAM1)) ||
(lvl & P(LVL, REM_RAM2)) ||
mrem) {
stats->rmt_dram++;
if (snoop & P(SNOOP, HIT))
stats->ld_shared++;
else
stats->ld_excl++;
}
}
if ((lvl & P(LVL, REM_CCE1)) ||
(lvl & P(LVL, REM_CCE2)) ||
mrem) {
if (snoop & P(SNOOP, HIT))
stats->rmt_hit++;
else if (snoop & P(SNOOP, HITM))
HITM_INC(rmt_hitm);
}
if ((lvl & P(LVL, MISS)))
stats->ld_miss++;
} else if (op & P(OP, STORE)) {
/* store */
stats->store++;
if (!daddr) {
stats->st_noadrs++;
return -1;
}
if (lvl & P(LVL, HIT)) {
if (lvl & P(LVL, UNC)) stats->st_uncache++;
if (lvl & P(LVL, L1 )) stats->st_l1hit++;
}
if (lvl & P(LVL, MISS))
if (lvl & P(LVL, L1)) stats->st_l1miss++;
} else {
/* unparsable data_src? */
stats->noparse++;
return -1;
}
if (!mi->daddr.map || !mi->iaddr.map) {
stats->nomap++;
return -1;
}
#undef P
#undef HITM_INC
return err;
}
void c2c_add_stats(struct c2c_stats *stats, struct c2c_stats *add)
{
stats->nr_entries += add->nr_entries;
stats->locks += add->locks;
stats->store += add->store;
stats->st_uncache += add->st_uncache;
stats->st_noadrs += add->st_noadrs;
stats->st_l1hit += add->st_l1hit;
stats->st_l1miss += add->st_l1miss;
stats->load += add->load;
stats->ld_excl += add->ld_excl;
stats->ld_shared += add->ld_shared;
stats->ld_uncache += add->ld_uncache;
stats->ld_io += add->ld_io;
stats->ld_miss += add->ld_miss;
stats->ld_noadrs += add->ld_noadrs;
stats->ld_fbhit += add->ld_fbhit;
stats->ld_l1hit += add->ld_l1hit;
stats->ld_l2hit += add->ld_l2hit;
stats->ld_llchit += add->ld_llchit;
stats->lcl_hitm += add->lcl_hitm;
stats->rmt_hitm += add->rmt_hitm;
stats->tot_hitm += add->tot_hitm;
stats->rmt_hit += add->rmt_hit;
stats->lcl_dram += add->lcl_dram;
stats->rmt_dram += add->rmt_dram;
stats->nomap += add->nomap;
stats->noparse += add->noparse;
}
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