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x86/intel_rdt: Modify the intel_pqr_state for better performance

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Currently we have pqr_state and rdt_default_state which store the cached
CLOSID/RMIDs and the user configured cpu default values respectively. We
touch both of these during context switch. Put all of them in one
structure so that we can spare a cache line.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: sai.praneeth.prakhya@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Link: http://lkml.kernel.org/r/1502304395-7166-3-git-send-email-vikas.shivappa@linux.intel.com
This commit is contained in:
Vikas Shivappa 2017-08-09 11:46:34 -07:00 committed by Thomas Gleixner
parent eda61c265f
commit a9110b552d
3 changed files with 26 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
arch/x86/include/asm/intel_rdt_sched.h
View File

@ -10,8 +10,10 @@
/**
* struct intel_pqr_state - State cache for the PQR MSR
* @rmid: The cached Resource Monitoring ID
* @closid: The cached Class Of Service ID
* @cur_rmid: The cached Resource Monitoring ID
* @cur_closid: The cached Class Of Service ID
* @default_rmid: The user assigned Resource Monitoring ID
* @default_closid: The user assigned cached Class Of Service ID
*
* The upper 32 bits of IA32_PQR_ASSOC contain closid and the
* lower 10 bits rmid. The update to IA32_PQR_ASSOC always
@ -22,12 +24,13 @@
* not change.
*/
struct intel_pqr_state {
u32 rmid;
u32 closid;
u32 cur_rmid;
u32 cur_closid;
u32 default_rmid;
u32 default_closid;
};
DECLARE_PER_CPU(struct intel_pqr_state, pqr_state);
DECLARE_PER_CPU_READ_MOSTLY(struct intel_pqr_state, rdt_cpu_default);
DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
@ -49,8 +52,9 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
*/
static void __intel_rdt_sched_in(void)
{
struct intel_pqr_state newstate = this_cpu_read(rdt_cpu_default);
struct intel_pqr_state *curstate = this_cpu_ptr(&pqr_state);
struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);
u32 closid = state->default_closid;
u32 rmid = state->default_rmid;
/*
* If this task has a closid/rmid assigned, use it.
@ -58,18 +62,18 @@ static void __intel_rdt_sched_in(void)
*/
if (static_branch_likely(&rdt_alloc_enable_key)) {
if (current->closid)
newstate.closid = current->closid;
closid = current->closid;
}
if (static_branch_likely(&rdt_mon_enable_key)) {
if (current->rmid)
newstate.rmid = current->rmid;
rmid = current->rmid;
}
if (newstate.closid != curstate->closid ||
newstate.rmid != curstate->rmid) {
*curstate = newstate;
wrmsr(IA32_PQR_ASSOC, newstate.rmid, newstate.closid);
if (closid != state->cur_closid || rmid != state->cur_rmid) {
state->cur_closid = closid;
state->cur_rmid = rmid;
wrmsr(IA32_PQR_ASSOC, rmid, closid);
}
}

10
arch/x86/kernel/cpu/intel_rdt.c
View File

@ -47,8 +47,6 @@ DEFINE_MUTEX(rdtgroup_mutex);
*/
DEFINE_PER_CPU(struct intel_pqr_state, pqr_state);
DEFINE_PER_CPU_READ_MOSTLY(struct intel_pqr_state, rdt_cpu_default);
/*
* Used to store the max resource name width and max resource data width
* to display the schemata in a tabular format
@ -550,10 +548,10 @@ static void clear_closid_rmid(int cpu)
{
struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);
per_cpu(rdt_cpu_default.closid, cpu) = 0;
per_cpu(rdt_cpu_default.rmid, cpu) = 0;
state->closid = 0;
state->rmid = 0;
state->default_closid = 0;
state->default_rmid = 0;
state->cur_closid = 0;
state->cur_rmid = 0;
wrmsr(IA32_PQR_ASSOC, 0, 0);
}

10
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
View File

@ -202,8 +202,8 @@ static void update_cpu_closid_rmid(void *info)
struct rdtgroup *r = info;
if (r) {
this_cpu_write(rdt_cpu_default.closid, r->closid);
this_cpu_write(rdt_cpu_default.rmid, r->mon.rmid);
this_cpu_write(pqr_state.default_closid, r->closid);
this_cpu_write(pqr_state.default_rmid, r->mon.rmid);
}
/*
@ -1733,7 +1733,7 @@ static int rdtgroup_rmdir_mon(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
/* Update per cpu rmid of the moved CPUs first */
for_each_cpu(cpu, &rdtgrp->cpu_mask)
per_cpu(rdt_cpu_default.rmid, cpu) = prdtgrp->mon.rmid;
per_cpu(pqr_state.default_rmid, cpu) = prdtgrp->mon.rmid;
/*
* Update the MSR on moved CPUs and CPUs which have moved
* task running on them.
@ -1774,8 +1774,8 @@ static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
/* Update per cpu closid and rmid of the moved CPUs first */
for_each_cpu(cpu, &rdtgrp->cpu_mask) {
per_cpu(rdt_cpu_default.closid, cpu) = rdtgroup_default.closid;
per_cpu(rdt_cpu_default.rmid, cpu) = rdtgroup_default.mon.rmid;
per_cpu(pqr_state.default_closid, cpu) = rdtgroup_default.closid;
per_cpu(pqr_state.default_rmid, cpu) = rdtgroup_default.mon.rmid;
}
/*