Commit 8ae68bfe authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Peter Zijlstra
Browse files

perf/amd/ibs: Enable streaming store filter 



IBS OP on future hardware supports recording samples only for instructions
that does streaming store. Like the existing IBS filters, samples pointing
to instruction which does not cause streaming store are discarded and IBS
restarts internally.

Example:

  $ perf record -e ibs_op/strmst=1/ -- <workload>

Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260216042530.1546-7-ravi.bangoria@amd.com
parent 8c63c4af

arch/x86/events/amd/ibs.c

+51 −0
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ static u32 ibs_caps; 


/* attr.config1 */

#define IBS_OP_CONFIG1_LDLAT_MASK		(0xFFFULL <<  0)

#define IBS_OP_CONFIG1_STRMST_MASK		    (1ULL << 12)

#define IBS_OP_CONFIG1_STRMST_SHIFT			    (12)



#define IBS_FETCH_CONFIG1_FETCHLAT_MASK		(0x7FFULL <<  0)
@@ -292,6 +294,14 @@ static bool perf_ibs_fetch_lat_event(struct perf_ibs *perf_ibs, 
	       (event->attr.config1 & IBS_FETCH_CONFIG1_FETCHLAT_MASK);

}



static bool perf_ibs_strmst_event(struct perf_ibs *perf_ibs,

				  struct perf_event *event)

{

	return perf_ibs == &perf_ibs_op &&

	       (ibs_caps & IBS_CAPS_STRMST_RMTSOCKET) &&

	       (event->attr.config1 & IBS_OP_CONFIG1_STRMST_MASK);

}



static int perf_ibs_init(struct perf_event *event)

{

	struct hw_perf_event *hwc = &event->hw;
@@ -419,6 +429,15 @@ static int perf_ibs_init(struct perf_event *event) 
		hwc->extra_reg.config |= fetchlat << IBS_FETCH_2_FETCHLAT_FILTER_SHIFT;

	}



	if (perf_ibs_strmst_event(perf_ibs, event)) {

		u64 strmst = event->attr.config1 & IBS_OP_CONFIG1_STRMST_MASK;



		strmst >>= IBS_OP_CONFIG1_STRMST_SHIFT;



		hwc->extra_reg.reg = perf_ibs->msr2;

		hwc->extra_reg.config |= strmst << IBS_OP_2_STRM_ST_FILTER_SHIFT;

	}



	/*

	 * If we modify hwc->sample_period, we also need to update

	 * hwc->last_period and hwc->period_left.
@@ -709,6 +728,8 @@ PMU_EVENT_ATTR_STRING(ldlat, ibs_op_ldlat_cap, "1"); 
PMU_EVENT_ATTR_STRING(dtlb_pgsize, ibs_op_dtlb_pgsize_cap, "1");

PMU_EVENT_ATTR_STRING(fetchlat, ibs_fetch_lat_format, "config1:0-10");

PMU_EVENT_ATTR_STRING(fetchlat, ibs_fetch_lat_cap, "1");

PMU_EVENT_ATTR_STRING(strmst, ibs_op_strmst_format, "config1:12");

PMU_EVENT_ATTR_STRING(strmst, ibs_op_strmst_cap, "1");



static umode_t

zen4_ibs_extensions_is_visible(struct kobject *kobj, struct attribute *attr, int i)
@@ -722,6 +743,12 @@ ibs_fetch_lat_is_visible(struct kobject *kobj, struct attribute *attr, int i) 
	return ibs_caps & IBS_CAPS_FETCHLAT ? attr->mode : 0;

}



static umode_t

ibs_op_strmst_is_visible(struct kobject *kobj, struct attribute *attr, int i)

{

	return ibs_caps & IBS_CAPS_STRMST_RMTSOCKET ? attr->mode : 0;

}



static umode_t

ibs_op_ldlat_is_visible(struct kobject *kobj, struct attribute *attr, int i)

{
@@ -770,6 +797,11 @@ static struct attribute *ibs_op_dtlb_pgsize_cap_attrs[] = { 
	NULL,

};



static struct attribute *ibs_op_strmst_cap_attrs[] = {

	&ibs_op_strmst_cap.attr.attr,

	NULL,

};



static struct attribute_group group_fetch_formats = {

	.name = "format",

	.attrs = fetch_attrs,
@@ -811,6 +843,12 @@ static struct attribute_group group_ibs_op_dtlb_pgsize_cap = { 
	.is_visible = ibs_op_dtlb_pgsize_is_visible,

};



static struct attribute_group group_ibs_op_strmst_cap = {

	.name = "caps",

	.attrs = ibs_op_strmst_cap_attrs,

	.is_visible = ibs_op_strmst_is_visible,

};



static const struct attribute_group *fetch_attr_groups[] = {

	&group_fetch_formats,

	&empty_caps_group,
@@ -856,6 +894,11 @@ static struct attribute *ibs_op_ldlat_format_attrs[] = { 
	NULL,

};



static struct attribute *ibs_op_strmst_format_attrs[] = {

	&ibs_op_strmst_format.attr.attr,

	NULL,

};



static struct attribute_group group_cnt_ctl = {

	.name = "format",

	.attrs = cnt_ctl_attrs,
@@ -880,6 +923,12 @@ static struct attribute_group group_ibs_op_ldlat_format = { 
	.is_visible = ibs_op_ldlat_is_visible,

};



static struct attribute_group group_ibs_op_strmst_format = {

	.name = "format",

	.attrs = ibs_op_strmst_format_attrs,

	.is_visible = ibs_op_strmst_is_visible,

};



static const struct attribute_group *op_attr_update[] = {

	&group_cnt_ctl,

	&group_op_l3missonly,
@@ -887,6 +936,8 @@ static const struct attribute_group *op_attr_update[] = { 
	&group_ibs_op_ldlat_cap,

	&group_ibs_op_ldlat_format,

	&group_ibs_op_dtlb_pgsize_cap,

	&group_ibs_op_strmst_cap,

	&group_ibs_op_strmst_format,

	NULL,

};

arch/x86/include/asm/amd/ibs.h

+2 −1
Original line number Diff line number Diff line
@@ -99,7 +99,8 @@ union ibs_op_data2 { 
			rmt_node:1,	/* 4: destination node */

			cache_hit_st:1,	/* 5: cache hit state */

			data_src_hi:2,	/* 6-7: data source high */

			reserved1:56;	/* 8-63: reserved */

			strm_st:1,	/* 8: streaming store */

			reserved1:55;	/* 9-63: reserved */

	};

};