From cca2c4b4465effee532dc53e1ee06a7fc92fc00f Mon Sep 17 00:00:00 2001 From: "Jayachandran C." Date: Thu, 17 Nov 2011 13:14:59 +0000 Subject: [PATCH] Do pmap update only on active CPUs. The pmap update_page/invalidate_page/invalidate_all operations has to be done only on active cpus. In the simplest case, if the process is not active on any other CPUs, we can just do the operation on the current CPU. This change replaces the call to smp_rendezvous() for these operations with smp_rendezvous_cpus() in case there more than one active CPU, or with a direct function call if there is just one active CPU. This change give significant performance increase in fork/exec benchmarks on XLR/XLS/XLP with 32 cpus. Reviewed by: alc --- sys/mips/mips/pmap.c | 180 ++++++++++++++++++------------------------- 1 file changed, 73 insertions(+), 107 deletions(-) diff --git a/sys/mips/mips/pmap.c b/sys/mips/mips/pmap.c index ec0241ea9ad..fc99035a054 100644 --- a/sys/mips/mips/pmap.c +++ b/sys/mips/mips/pmap.c @@ -181,7 +181,6 @@ static pt_entry_t init_pte_prot(vm_offset_t va, vm_page_t m, vm_prot_t prot); #ifdef SMP static void pmap_invalidate_page_action(void *arg); -static void pmap_invalidate_all_action(void *arg); static void pmap_update_page_action(void *arg); #endif @@ -622,72 +621,84 @@ pmap_init(void) * Low level helper routines..... ***************************************************/ +#ifdef SMP static __inline void -pmap_invalidate_all_local(pmap_t pmap) +pmap_call_on_active_cpus(pmap_t pmap, void (*fn)(void *), void *arg) { - u_int cpuid; + int cpuid, cpu, self; + cpuset_t active_cpus; - cpuid = PCPU_GET(cpuid); - - if (pmap == kernel_pmap) { - tlb_invalidate_all(); - return; + sched_pin(); + if (is_kernel_pmap(pmap)) { + smp_rendezvous(NULL, fn, NULL, arg); + goto out; + } + /* Force ASID update on inactive CPUs */ + CPU_FOREACH(cpu) { + if (!CPU_ISSET(cpu, &pmap->pm_active)) + pmap->pm_asid[cpu].gen = 0; } - if (CPU_ISSET(cpuid, &pmap->pm_active)) - tlb_invalidate_all_user(pmap); - else - pmap->pm_asid[cpuid].gen = 0; -} - -#ifdef SMP -static void -pmap_invalidate_all(pmap_t pmap) -{ - - smp_rendezvous(0, pmap_invalidate_all_action, 0, pmap); -} - -static void -pmap_invalidate_all_action(void *arg) -{ - - pmap_invalidate_all_local((pmap_t)arg); -} -#else -static void -pmap_invalidate_all(pmap_t pmap) -{ - - pmap_invalidate_all_local(pmap); -} -#endif - -static __inline void -pmap_invalidate_page_local(pmap_t pmap, vm_offset_t va) -{ - u_int cpuid; - cpuid = PCPU_GET(cpuid); + /* + * XXX: barrier/locking for active? + * + * Take a snapshot of active here, any further changes are ignored. + * tlb update/invalidate should be harmless on inactive CPUs + */ + active_cpus = pmap->pm_active; + self = CPU_ISSET(cpuid, &active_cpus); + CPU_CLR(cpuid, &active_cpus); + /* Optimize for the case where this cpu is the only active one */ + if (CPU_EMPTY(&active_cpus)) { + if (self) + fn(arg); + } else { + if (self) + CPU_SET(cpuid, &active_cpus); + smp_rendezvous_cpus(active_cpus, NULL, fn, NULL, arg); + } +out: + sched_unpin(); +} +#else /* !SMP */ +static __inline void +pmap_call_on_active_cpus(pmap_t pmap, void (*fn)(void *), void *arg) +{ + int cpuid; if (is_kernel_pmap(pmap)) { - tlb_invalidate_address(pmap, va); + fn(arg); return; } - if (pmap->pm_asid[cpuid].gen != PCPU_GET(asid_generation)) - return; - else if (!CPU_ISSET(cpuid, &pmap->pm_active)) { + cpuid = PCPU_GET(cpuid); + if (!CPU_ISSET(cpuid, &pmap->pm_active)) pmap->pm_asid[cpuid].gen = 0; - return; - } - tlb_invalidate_address(pmap, va); + else + fn(arg); +} +#endif /* SMP */ + +static void +pmap_invalidate_all(pmap_t pmap) +{ + + pmap_call_on_active_cpus(pmap, + (void (*)(void *))tlb_invalidate_all_user, pmap); } -#ifdef SMP struct pmap_invalidate_page_arg { pmap_t pmap; vm_offset_t va; }; +static void +pmap_invalidate_page_action(void *arg) +{ + struct pmap_invalidate_page_arg *p = arg; + + tlb_invalidate_address(p->pmap, p->va); +} + static void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { @@ -695,52 +706,23 @@ pmap_invalidate_page(pmap_t pmap, vm_offset_t va) arg.pmap = pmap; arg.va = va; - smp_rendezvous(0, pmap_invalidate_page_action, 0, &arg); + pmap_call_on_active_cpus(pmap, pmap_invalidate_page_action, &arg); } -static void -pmap_invalidate_page_action(void *arg) -{ - struct pmap_invalidate_page_arg *p = arg; - - pmap_invalidate_page_local(p->pmap, p->va); -} -#else -static void -pmap_invalidate_page(pmap_t pmap, vm_offset_t va) -{ - - pmap_invalidate_page_local(pmap, va); -} -#endif - -static __inline void -pmap_update_page_local(pmap_t pmap, vm_offset_t va, pt_entry_t pte) -{ - u_int cpuid; - - cpuid = PCPU_GET(cpuid); - - if (is_kernel_pmap(pmap)) { - tlb_update(pmap, va, pte); - return; - } - if (pmap->pm_asid[cpuid].gen != PCPU_GET(asid_generation)) - return; - else if (!CPU_ISSET(cpuid, &pmap->pm_active)) { - pmap->pm_asid[cpuid].gen = 0; - return; - } - tlb_update(pmap, va, pte); -} - -#ifdef SMP struct pmap_update_page_arg { pmap_t pmap; vm_offset_t va; pt_entry_t pte; }; +static void +pmap_update_page_action(void *arg) +{ + struct pmap_update_page_arg *p = arg; + + tlb_update(p->pmap, p->va, p->pte); +} + static void pmap_update_page(pmap_t pmap, vm_offset_t va, pt_entry_t pte) { @@ -749,25 +731,9 @@ pmap_update_page(pmap_t pmap, vm_offset_t va, pt_entry_t pte) arg.pmap = pmap; arg.va = va; arg.pte = pte; - smp_rendezvous(0, pmap_update_page_action, 0, &arg); + pmap_call_on_active_cpus(pmap, pmap_update_page_action, &arg); } -static void -pmap_update_page_action(void *arg) -{ - struct pmap_update_page_arg *p = arg; - - pmap_update_page_local(p->pmap, p->va, p->pte); -} -#else -static void -pmap_update_page(pmap_t pmap, vm_offset_t va, pt_entry_t pte) -{ - - pmap_update_page_local(pmap, va, pte); -} -#endif - /* * Routine: pmap_extract * Function: @@ -3213,7 +3179,7 @@ pmap_emulate_modified(pmap_t pmap, vm_offset_t va) #ifdef SMP /* It is possible that some other CPU changed m-bit */ if (!pte_test(pte, PTE_V) || pte_test(pte, PTE_D)) { - pmap_update_page_local(pmap, va, *pte); + tlb_update(pmap, va, *pte); PMAP_UNLOCK(pmap); return (0); } @@ -3227,7 +3193,7 @@ pmap_emulate_modified(pmap_t pmap, vm_offset_t va) return (1); } pte_set(pte, PTE_D); - pmap_update_page_local(pmap, va, *pte); + tlb_update(pmap, va, *pte); pa = TLBLO_PTE_TO_PA(*pte); if (!page_is_managed(pa)) panic("pmap_emulate_modified: unmanaged page");