Commit 19c635ab authored by Vikas Shivappa's avatar Vikas Shivappa Committed by Thomas Gleixner

x86/intel_rdt/mba_sc: Enable/disable MBA software controller

Currently user does memory bandwidth allocation(MBA) by specifying the
bandwidth in percentage via the resctrl schemata file:
	"/sys/fs/resctrl/schemata"

Add a new mount option "mba_MBps" to enable the user to specify MBA
in MBps:

$mount -t resctrl resctrl [-o cdp[,cdpl2][mba_MBps]] /sys/fs/resctrl
Signed-off-by: default avatarVikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/1524263781-14267-3-git-send-email-vikas.shivappa@linux.intel.com
parent d6c64a4f
......@@ -230,6 +230,14 @@ static inline void cache_alloc_hsw_probe(void)
rdt_alloc_capable = true;
}
bool is_mba_sc(struct rdt_resource *r)
{
if (!r)
return rdt_resources_all[RDT_RESOURCE_MBA].membw.mba_sc;
return r->membw.mba_sc;
}
/*
* rdt_get_mb_table() - get a mapping of bandwidth(b/w) percentage values
* exposed to user interface and the h/w understandable delay values.
......
......@@ -259,6 +259,7 @@ struct rdt_cache {
* @min_bw: Minimum memory bandwidth percentage user can request
* @bw_gran: Granularity at which the memory bandwidth is allocated
* @delay_linear: True if memory B/W delay is in linear scale
* @mba_sc: True if MBA software controller(mba_sc) is enabled
* @mb_map: Mapping of memory B/W percentage to memory B/W delay
*/
struct rdt_membw {
......@@ -266,6 +267,7 @@ struct rdt_membw {
u32 min_bw;
u32 bw_gran;
u32 delay_linear;
bool mba_sc;
u32 *mb_map;
};
......@@ -445,6 +447,7 @@ void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
void mbm_setup_overflow_handler(struct rdt_domain *dom,
unsigned long delay_ms);
void mbm_handle_overflow(struct work_struct *work);
bool is_mba_sc(struct rdt_resource *r);
void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms);
void cqm_handle_limbo(struct work_struct *work);
bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d);
......
......@@ -1005,6 +1005,11 @@ static void l2_qos_cfg_update(void *arg)
wrmsrl(IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
}
static inline bool is_mba_linear(void)
{
return rdt_resources_all[RDT_RESOURCE_MBA].membw.delay_linear;
}
static int set_cache_qos_cfg(int level, bool enable)
{
void (*update)(void *arg);
......@@ -1041,6 +1046,25 @@ static int set_cache_qos_cfg(int level, bool enable)
return 0;
}
/*
* Enable or disable the MBA software controller
* which helps user specify bandwidth in MBps.
* MBA software controller is supported only if
* MBM is supported and MBA is in linear scale.
*/
static int set_mba_sc(bool mba_sc)
{
struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA];
if (!is_mbm_enabled() || !is_mba_linear() ||
mba_sc == is_mba_sc(r))
return -EINVAL;
r->membw.mba_sc = mba_sc;
return 0;
}
static int cdp_enable(int level, int data_type, int code_type)
{
struct rdt_resource *r_ldata = &rdt_resources_all[data_type];
......@@ -1123,6 +1147,10 @@ static int parse_rdtgroupfs_options(char *data)
ret = cdpl2_enable();
if (ret)
goto out;
} else if (!strcmp(token, "mba_MBps")) {
ret = set_mba_sc(true);
if (ret)
goto out;
} else {
ret = -EINVAL;
goto out;
......@@ -1445,6 +1473,8 @@ static void rdt_kill_sb(struct super_block *sb)
cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
set_mba_sc(false);
/*Put everything back to default values. */
for_each_alloc_enabled_rdt_resource(r)
reset_all_ctrls(r);
......
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