Hi Babu,
On 12/1/2022 7:37 AM, Babu Moger wrote:
> The current event configuration for mbm_local_bytes can be changed by
> the user by writing to the configuration file
> /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config.
>
Same comments about subject line and usage of "current".
> The event configuration settings are domain specific and will affect all
> the CPUs in the domain.
>
> Following are the types of events supported:
> ==== ===========================================================
> Bits Description
> ==== ===========================================================
> 6 Dirty Victims from the QOS domain to all types of memory
> 5 Reads to slow memory in the non-local NUMA domain
> 4 Reads to slow memory in the local NUMA domain
> 3 Non-temporal writes to non-local NUMA domain
> 2 Non-temporal writes to local NUMA domain
> 1 Reads to memory in the non-local NUMA domain
> 0 Reads to memory in the local NUMA domain
> ==== ===========================================================
>
> For example:
> To change the mbm_local_bytes_config to count all the non-temporal writes
> on domain 0, the bits 2 and 3 needs to be set which is 1100b (in hex 0xc).
> Run the command.
> $echo 0=0xc > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
>
> To change the mbm_local_bytes to count only reads to local NUMA domain 1,
> the bit 0 needs to be set which 1b (in hex 0x1). Run the command.
> $echo 1=0x1 > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 29 ++++++++++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 8a22a652a6e8..6897c480ae55 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1641,6 +1641,32 @@ static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
> return ret ?: nbytes;
> }
>
> +static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
> + char *buf, size_t nbytes,
> + loff_t off)
> +{
> + struct rdt_resource *r = of->kn->parent->priv;
> + int ret;
> +
> + /* Valid input requires a trailing newline */
> + if (nbytes == 0 || buf[nbytes - 1] != '\n')
> + return -EINVAL;
> +
> + cpus_read_lock();
> + mutex_lock(&rdtgroup_mutex);
> +
> + rdt_last_cmd_clear();
> +
> + buf[nbytes - 1] = '\0';
> +
> + ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
> +
> + mutex_unlock(&rdtgroup_mutex);
> + cpus_read_unlock();
> +
> + return ret ?: nbytes;
> +}
> +
> /* rdtgroup information files for one cache resource. */
> static struct rftype res_common_files[] = {
> {
> @@ -1748,9 +1774,10 @@ static struct rftype res_common_files[] = {
> },
> {
> .name = "mbm_local_bytes_config",
> - .mode = 0444,
> + .mode = 0644,
> .kf_ops = &rdtgroup_kf_single_ops,
> .seq_show = mbm_local_bytes_config_show,
> + .write = mbm_local_bytes_config_write,
> },
> {
> .name = "cpus",
>
>
With the subject and changelog comments addressed:
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reinette
