Commit-ID: a9110b552d44fedbd1221eb0e5bde81da32d9350 Gitweb: http://git.kernel.org/tip/a9110b552d44fedbd1221eb0e5bde81da32d9350 Author: Vikas Shivappa <vikas.shiva...@linux.intel.com> AuthorDate: Wed, 9 Aug 2017 11:46:34 -0700 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Mon, 14 Aug 2017 11:47:47 +0200
x86/intel_rdt: Modify the intel_pqr_state for better performance 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 <t...@linutronix.de> Signed-off-by: Vikas Shivappa <vikas.shiva...@linux.intel.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: ravi.v.shan...@intel.com Cc: tony.l...@intel.com Cc: fenghua...@intel.com Cc: pet...@infradead.org Cc: eran...@google.com Cc: sai.praneeth.prak...@intel.com Cc: a...@linux.intel.com Cc: davi...@google.com Link: http://lkml.kernel.org/r/1502304395-7166-3-git-send-email-vikas.shiva...@linux.intel.com --- arch/x86/include/asm/intel_rdt_sched.h | 30 +++++++++++++++++------------- arch/x86/kernel/cpu/intel_rdt.c | 10 ++++------ arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 10 +++++----- 3 files changed, 26 insertions(+), 24 deletions(-) diff --git a/arch/x86/include/asm/intel_rdt_sched.h b/arch/x86/include/asm/intel_rdt_sched.h index 3badc0a..b4bbf8b 100644 --- a/arch/x86/include/asm/intel_rdt_sched.h +++ b/arch/x86/include/asm/intel_rdt_sched.h @@ -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); } } diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index 4b9edb2..97c8d83 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -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); } diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 2621ae3..86a6979 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -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; } /*
