diff options
| -rw-r--r-- | sys/vm/vm_pageout.c | 63 |
1 files changed, 31 insertions, 32 deletions
diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c index 34a3a4f9048e..c966c356908a 100644 --- a/sys/vm/vm_pageout.c +++ b/sys/vm/vm_pageout.c @@ -165,11 +165,10 @@ SYSCTL_INT(_vm, OID_AUTO, pageout_update_period, CTLFLAG_RWTUN, &vm_pageout_update_period, 0, "Maximum active LRU update period"); -/* Access with get_pageout_threads_per_domain(). */ -static int pageout_threads_per_domain = 1; -SYSCTL_INT(_vm, OID_AUTO, pageout_threads_per_domain, CTLFLAG_RDTUN, - &pageout_threads_per_domain, 0, - "Number of worker threads comprising each per-domain pagedaemon"); +static int pageout_cpus_per_thread = 16; +SYSCTL_INT(_vm, OID_AUTO, pageout_cpus_per_thread, CTLFLAG_RDTUN, + &pageout_cpus_per_thread, 0, + "Number of CPUs per pagedaemon worker thread"); SYSCTL_INT(_vm, OID_AUTO, lowmem_period, CTLFLAG_RWTUN, &lowmem_period, 0, "Low memory callback period"); @@ -2200,38 +2199,38 @@ vm_pageout_helper(void *arg) } static int -get_pageout_threads_per_domain(void) +get_pageout_threads_per_domain(const struct vm_domain *vmd) { - static bool resolved = false; - int half_cpus_per_dom; + unsigned total_pageout_threads, eligible_cpus, domain_cpus; + + if (VM_DOMAIN_EMPTY(vmd->vmd_domain)) + return (0); /* - * This is serialized externally by the sorted autoconfig portion of - * boot. + * Semi-arbitrarily constrain pagedaemon threads to less than half the + * total number of CPUs in the system as an upper limit. */ - if (__predict_true(resolved)) - return (pageout_threads_per_domain); + if (pageout_cpus_per_thread < 2) + pageout_cpus_per_thread = 2; + else if (pageout_cpus_per_thread > mp_ncpus) + pageout_cpus_per_thread = mp_ncpus; + + total_pageout_threads = howmany(mp_ncpus, pageout_cpus_per_thread); + domain_cpus = CPU_COUNT(&cpuset_domain[vmd->vmd_domain]); + + /* Pagedaemons are not run in empty domains. */ + eligible_cpus = mp_ncpus; + for (unsigned i = 0; i < vm_ndomains; i++) + if (VM_DOMAIN_EMPTY(i)) + eligible_cpus -= CPU_COUNT(&cpuset_domain[i]); /* - * Semi-arbitrarily constrain pagedaemon threads to less than half the - * total number of threads in the system as an insane upper limit. + * Assign a portion of the total pageout threads to this domain + * corresponding to the fraction of pagedaemon-eligible CPUs in the + * domain. In asymmetric NUMA systems, domains with more CPUs may be + * allocated more threads than domains with fewer CPUs. */ - half_cpus_per_dom = howmany(mp_ncpus / vm_ndomains, 2); - - if (pageout_threads_per_domain < 1) { - printf("Invalid tuneable vm.pageout_threads_per_domain value: " - "%d out of valid range: [1-%d]; clamping to 1\n", - pageout_threads_per_domain, half_cpus_per_dom); - pageout_threads_per_domain = 1; - } else if (pageout_threads_per_domain > half_cpus_per_dom) { - printf("Invalid tuneable vm.pageout_threads_per_domain value: " - "%d out of valid range: [1-%d]; clamping to %d\n", - pageout_threads_per_domain, half_cpus_per_dom, - half_cpus_per_dom); - pageout_threads_per_domain = half_cpus_per_dom; - } - resolved = true; - return (pageout_threads_per_domain); + return (howmany(total_pageout_threads * domain_cpus, eligible_cpus)); } /* @@ -2288,7 +2287,7 @@ vm_pageout_init_domain(int domain) "pidctrl", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, ""); pidctrl_init_sysctl(&vmd->vmd_pid, SYSCTL_CHILDREN(oid)); - vmd->vmd_inactive_threads = get_pageout_threads_per_domain(); + vmd->vmd_inactive_threads = get_pageout_threads_per_domain(vmd); } static void @@ -2343,7 +2342,6 @@ vm_pageout(void) p = curproc; td = curthread; - pageout_threads = get_pageout_threads_per_domain(); mtx_init(&vm_oom_ratelim_mtx, "vmoomr", NULL, MTX_DEF); swap_pager_swap_init(); @@ -2363,6 +2361,7 @@ vm_pageout(void) panic("starting pageout for domain %d: %d\n", i, error); } + pageout_threads = VM_DOMAIN(i)->vmd_inactive_threads; for (j = 0; j < pageout_threads - 1; j++) { error = kthread_add(vm_pageout_helper, (void *)(uintptr_t)i, p, NULL, 0, 0, |