Commit 87f01cc2 authored by Tony Luck's avatar Tony Luck Committed by Ingo Molnar

perf/x86/mbm: Add memory bandwidth monitoring event management

Includes all the core infrastructure to measure the total_bytes and
bandwidth.

We have per socket counters for both total system wide L3 external
bytes and local socket memory-controller bytes. The OS does MSR writes
to MSR_IA32_QM_EVTSEL and MSR_IA32_QM_CTR to read the counters and
uses the IA32_PQR_ASSOC_MSR to associate the RMID with the task. The
tasks have a common RMID for CQM (cache quality of service monitoring)
and MBM. Hence most of the scheduling code is reused from CQM.
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
[ Restructured rmid_read to not have an obvious hole, removed MBM_CNTR_MAX as its unused. ]
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarVikas Shivappa <vikas.shivappa@linux.intel.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: fenghua.yu@intel.com
Cc: h.peter.anvin@intel.com
Cc: ravi.v.shankar@intel.com
Cc: vikas.shivappa@intel.com
Link: http://lkml.kernel.org/r/abd7aac9a18d93b95b985b931cf258df0164746d.1457723885.git.tony.luck@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 33c3cc7a
......@@ -13,6 +13,8 @@
#define MSR_IA32_QM_CTR 0x0c8e
#define MSR_IA32_QM_EVTSEL 0x0c8d
#define MBM_CNTR_WIDTH 24
static u32 cqm_max_rmid = -1;
static unsigned int cqm_l3_scale; /* supposedly cacheline size */
static bool cqm_enabled, mbm_enabled;
......@@ -62,6 +64,16 @@ static struct sample *mbm_total;
*/
static struct sample *mbm_local;
#define pkg_id topology_physical_package_id(smp_processor_id())
/*
* rmid_2_index returns the index for the rmid in mbm_local/mbm_total array.
* mbm_total[] and mbm_local[] are linearly indexed by socket# * max number of
* rmids per socket, an example is given below
* RMID1 of Socket0: vrmid = 1
* RMID1 of Socket1: vrmid = 1 * (cqm_max_rmid + 1) + 1
* RMID1 of Socket2: vrmid = 2 * (cqm_max_rmid + 1) + 1
*/
#define rmid_2_index(rmid) ((pkg_id * (cqm_max_rmid + 1)) + rmid)
/*
* Protects cache_cgroups and cqm_rmid_free_lru and cqm_rmid_limbo_lru.
* Also protects event->hw.cqm_rmid
......@@ -84,9 +96,13 @@ static cpumask_t cqm_cpumask;
#define RMID_VAL_ERROR (1ULL << 63)
#define RMID_VAL_UNAVAIL (1ULL << 62)
#define QOS_L3_OCCUP_EVENT_ID (1 << 0)
#define QOS_EVENT_MASK QOS_L3_OCCUP_EVENT_ID
/*
* Event IDs are used to program IA32_QM_EVTSEL before reading event
* counter from IA32_QM_CTR
*/
#define QOS_L3_OCCUP_EVENT_ID 0x01
#define QOS_MBM_TOTAL_EVENT_ID 0x02
#define QOS_MBM_LOCAL_EVENT_ID 0x03
/*
* This is central to the rotation algorithm in __intel_cqm_rmid_rotate().
......@@ -428,10 +444,17 @@ static bool __conflict_event(struct perf_event *a, struct perf_event *b)
struct rmid_read {
u32 rmid;
u32 evt_type;
atomic64_t value;
};
static void __intel_cqm_event_count(void *info);
static void init_mbm_sample(u32 rmid, u32 evt_type);
static bool is_mbm_event(int e)
{
return (e >= QOS_MBM_TOTAL_EVENT_ID && e <= QOS_MBM_LOCAL_EVENT_ID);
}
/*
* Exchange the RMID of a group of events.
......@@ -873,6 +896,68 @@ static void intel_cqm_rmid_rotate(struct work_struct *work)
schedule_delayed_work(&intel_cqm_rmid_work, delay);
}
static u64 update_sample(unsigned int rmid, u32 evt_type, int first)
{
struct sample *mbm_current;
u32 vrmid = rmid_2_index(rmid);
u64 val, bytes, shift;
u32 eventid;
if (evt_type == QOS_MBM_LOCAL_EVENT_ID) {
mbm_current = &mbm_local[vrmid];
eventid = QOS_MBM_LOCAL_EVENT_ID;
} else {
mbm_current = &mbm_total[vrmid];
eventid = QOS_MBM_TOTAL_EVENT_ID;
}
wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
rdmsrl(MSR_IA32_QM_CTR, val);
if (val & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL))
return mbm_current->total_bytes;
if (first) {
mbm_current->prev_msr = val;
mbm_current->total_bytes = 0;
return mbm_current->total_bytes;
}
shift = 64 - MBM_CNTR_WIDTH;
bytes = (val << shift) - (mbm_current->prev_msr << shift);
bytes >>= shift;
bytes *= cqm_l3_scale;
mbm_current->total_bytes += bytes;
mbm_current->prev_msr = val;
return mbm_current->total_bytes;
}
static u64 rmid_read_mbm(unsigned int rmid, u32 evt_type)
{
return update_sample(rmid, evt_type, 0);
}
static void __intel_mbm_event_init(void *info)
{
struct rmid_read *rr = info;
update_sample(rr->rmid, rr->evt_type, 1);
}
static void init_mbm_sample(u32 rmid, u32 evt_type)
{
struct rmid_read rr = {
.rmid = rmid,
.evt_type = evt_type,
.value = ATOMIC64_INIT(0),
};
/* on each socket, init sample */
on_each_cpu_mask(&cqm_cpumask, __intel_mbm_event_init, &rr, 1);
}
/*
* Find a group and setup RMID.
*
......@@ -893,6 +978,8 @@ static void intel_cqm_setup_event(struct perf_event *event,
/* All tasks in a group share an RMID */
event->hw.cqm_rmid = rmid;
*group = iter;
if (is_mbm_event(event->attr.config))
init_mbm_sample(rmid, event->attr.config);
return;
}
......@@ -909,6 +996,9 @@ static void intel_cqm_setup_event(struct perf_event *event,
else
rmid = __get_rmid();
if (is_mbm_event(event->attr.config))
init_mbm_sample(rmid, event->attr.config);
event->hw.cqm_rmid = rmid;
}
......@@ -930,6 +1020,9 @@ static void intel_cqm_event_read(struct perf_event *event)
if (!__rmid_valid(rmid))
goto out;
if (is_mbm_event(event->attr.config))
val = rmid_read_mbm(rmid, event->attr.config);
else
val = __rmid_read(rmid);
/*
......@@ -961,6 +1054,17 @@ static inline bool cqm_group_leader(struct perf_event *event)
return !list_empty(&event->hw.cqm_groups_entry);
}
static void __intel_mbm_event_count(void *info)
{
struct rmid_read *rr = info;
u64 val;
val = rmid_read_mbm(rr->rmid, rr->evt_type);
if (val & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL))
return;
atomic64_add(val, &rr->value);
}
static u64 intel_cqm_event_count(struct perf_event *event)
{
unsigned long flags;
......@@ -1014,7 +1118,12 @@ static u64 intel_cqm_event_count(struct perf_event *event)
if (!__rmid_valid(rr.rmid))
goto out;
if (is_mbm_event(event->attr.config)) {
rr.evt_type = event->attr.config;
on_each_cpu_mask(&cqm_cpumask, __intel_mbm_event_count, &rr, 1);
} else {
on_each_cpu_mask(&cqm_cpumask, __intel_cqm_event_count, &rr, 1);
}
raw_spin_lock_irqsave(&cache_lock, flags);
if (event->hw.cqm_rmid == rr.rmid)
......@@ -1129,7 +1238,8 @@ static int intel_cqm_event_init(struct perf_event *event)
if (event->attr.type != intel_cqm_pmu.type)
return -ENOENT;
if (event->attr.config & ~QOS_EVENT_MASK)
if ((event->attr.config < QOS_L3_OCCUP_EVENT_ID) ||
(event->attr.config > QOS_MBM_LOCAL_EVENT_ID))
return -EINVAL;
/* unsupported modes and filters */
......
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