Re: [PATCH] perf, ibs: Add sysfs support

[Robert Richter <robert.richter@amd.com>]

Peter,

the patch below should be for tip:perf/core and included with the
merge window for v3.7 if possible.

Please apply if it looks good to you.

Thanks,

-Robert

On 12.09.12 12:59:44, Robert Richter wrote:
> Add sysfs format entries for ibs pmus:
> 
>  # find /sys/bus/event_source/devices/ibs_*/format
>  /sys/bus/event_source/devices/ibs_fetch/format
>  /sys/bus/event_source/devices/ibs_fetch/format/rand_en
>  /sys/bus/event_source/devices/ibs_op/format
>  /sys/bus/event_source/devices/ibs_op/format/cnt_ctl
> 
> This allows to specify following ibs options:
> 
>  $ perf record -e ibs_fetch/rand_en=1/GH ...
>  $ perf record -e ibs_op/cnt_ctl=1/GH ...
> 
> Option cnt_ctl is only enabled if the IBS_CAPS_OPCNT bit is set in ibs
> cpuid feature flags (family 10h RevC and above).
> 
> Signed-off-by: Robert Richter <robert.richter@amd.com>
> ---
>  arch/x86/kernel/cpu/perf_event_amd_ibs.c |   38 +++++++++++++++++++++++++++++-
>  1 files changed, 37 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
> index eebd5ff..4af8275 100644
> --- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
> +++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
> @@ -51,6 +51,11 @@ struct perf_ibs {
>  	unsigned long	offset_mask[1];
>  	int		offset_max;
>  	struct cpu_perf_ibs __percpu *pcpu;
> +
> +	struct attribute **format_attrs;
> +	struct attribute_group format_group;
> +	const struct attribute_group *attr_groups[2];
> +
>  	u64		(*get_count)(u64 config);
>  };
>  
> @@ -446,6 +451,19 @@ static void perf_ibs_del(struct perf_event *event, int flags)
>  
>  static void perf_ibs_read(struct perf_event *event) { }
>  
> +PMU_FORMAT_ATTR(rand_en,	"config:57");
> +PMU_FORMAT_ATTR(cnt_ctl,	"config:19");
> +
> +static struct attribute *ibs_fetch_format_attrs[] = {
> +	&format_attr_rand_en.attr,
> +	NULL,
> +};
> +
> +static struct attribute *ibs_op_format_attrs[] = {
> +	NULL,	/* &format_attr_cnt_ctl.attr if IBS_CAPS_OPCNT */
> +	NULL,
> +};
> +
>  static struct perf_ibs perf_ibs_fetch = {
>  	.pmu = {
>  		.task_ctx_nr	= perf_invalid_context,
> @@ -465,6 +483,7 @@ static struct perf_ibs perf_ibs_fetch = {
>  	.max_period		= IBS_FETCH_MAX_CNT << 4,
>  	.offset_mask		= { MSR_AMD64_IBSFETCH_REG_MASK },
>  	.offset_max		= MSR_AMD64_IBSFETCH_REG_COUNT,
> +	.format_attrs		= ibs_fetch_format_attrs,
>  
>  	.get_count		= get_ibs_fetch_count,
>  };
> @@ -488,6 +507,7 @@ static struct perf_ibs perf_ibs_op = {
>  	.max_period		= IBS_OP_MAX_CNT << 4,
>  	.offset_mask		= { MSR_AMD64_IBSOP_REG_MASK },
>  	.offset_max		= MSR_AMD64_IBSOP_REG_COUNT,
> +	.format_attrs		= ibs_op_format_attrs,
>  
>  	.get_count		= get_ibs_op_count,
>  };
> @@ -597,6 +617,16 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
>  
>  	perf_ibs->pcpu = pcpu;
>  
> +	/* register attributes */
> +	if (perf_ibs->format_attrs[0]) {
> +		memset(&perf_ibs->format_group, 0, sizeof(perf_ibs->format_group));
> +		perf_ibs->format_group.name = "format";
> +		perf_ibs->format_group.attrs = perf_ibs->format_attrs;
> +		memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
> +		perf_ibs->attr_groups[0] = &perf_ibs->format_group;
> +		perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
> +	}
> +
>  	ret = perf_pmu_register(&perf_ibs->pmu, name, -1);
>  	if (ret) {
>  		perf_ibs->pcpu = NULL;
> @@ -608,13 +638,19 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
>  
>  static __init int perf_event_ibs_init(void)
>  {
> +	struct attribute **attr = ibs_op_format_attrs;
> +
>  	if (!ibs_caps)
>  		return -ENODEV;	/* ibs not supported by the cpu */
>  
>  	perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
> -	if (ibs_caps & IBS_CAPS_OPCNT)
> +
> +	if (ibs_caps & IBS_CAPS_OPCNT) {
>  		perf_ibs_op.config_mask |= IBS_OP_CNT_CTL;
> +		*attr++ = &format_attr_cnt_ctl.attr;
> +	}
>  	perf_ibs_pmu_init(&perf_ibs_op, "ibs_op");
> +
>  	register_nmi_handler(NMI_LOCAL, perf_ibs_nmi_handler, 0, "perf_ibs");
>  	printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps);
>  
> -- 
> 1.7.8.6
> 

-- 
Advanced Micro Devices, Inc.
Operating System Research Center