diff options
Diffstat (limited to 'arch/x86/kernel/tlb_uv.c')
| -rw-r--r-- | arch/x86/kernel/tlb_uv.c | 76 |
1 files changed, 73 insertions, 3 deletions
diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c index c8661779c51e..dc6a68312758 100644 --- a/arch/x86/kernel/tlb_uv.c +++ b/arch/x86/kernel/tlb_uv.c @@ -44,6 +44,9 @@ static int timeout_base_ns[] = { }; static int timeout_us; static int nobau; +static int baudisabled; +static spinlock_t disable_lock; +static cycles_t congested_cycles; /* tunables: */ static int max_bau_concurrent = MAX_BAU_CONCURRENT; @@ -519,6 +522,35 @@ static inline int atomic_inc_unless_ge(spinlock_t *lock, atomic_t *v, int u) return 1; } +/* + * Completions are taking a very long time due to a congested numalink + * network. + */ +static void +disable_for_congestion(struct bau_control *bcp, struct ptc_stats *stat) +{ + int tcpu; + struct bau_control *tbcp; + + /* let only one cpu do this disabling */ + spin_lock(&disable_lock); + if (!baudisabled && bcp->period_requests && + ((bcp->period_time / bcp->period_requests) > congested_cycles)) { + /* it becomes this cpu's job to turn on the use of the + BAU again */ + baudisabled = 1; + bcp->set_bau_off = 1; + bcp->set_bau_on_time = get_cycles() + + sec_2_cycles(bcp->congested_period); + stat->s_bau_disabled++; + for_each_present_cpu(tcpu) { + tbcp = &per_cpu(bau_control, tcpu); + tbcp->baudisabled = 1; + } + } + spin_unlock(&disable_lock); +} + /** * uv_flush_send_and_wait * @@ -681,6 +713,14 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc, if (time2 > time1) { elapsed = time2 - time1; stat->s_time += elapsed; + if ((completion_status == FLUSH_COMPLETE) && (try == 1)) { + bcp->period_requests++; + bcp->period_time += elapsed; + if ((elapsed > congested_cycles) && + (bcp->period_requests > bcp->congested_reps)) { + disable_for_congestion(bcp, stat); + } + } } else stat->s_requestor--; /* don't count this one */ if (completion_status == FLUSH_COMPLETE && try > 1) @@ -747,12 +787,32 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask, struct cpumask *flush_mask; struct ptc_stats *stat; struct bau_control *bcp; + struct bau_control *tbcp; /* kernel was booted 'nobau' */ if (nobau) return cpumask; bcp = &per_cpu(bau_control, cpu); + stat = &per_cpu(ptcstats, cpu); + + /* bau was disabled due to slow response */ + if (bcp->baudisabled) { + /* the cpu that disabled it must re-enable it */ + if (bcp->set_bau_off) { + if (get_cycles() >= bcp->set_bau_on_time) { + stat->s_bau_reenabled++; + baudisabled = 0; + for_each_present_cpu(tcpu) { + tbcp = &per_cpu(bau_control, tcpu); + tbcp->baudisabled = 0; + tbcp->period_requests = 0; + tbcp->period_time = 0; + } + } + } + return cpumask; + } /* * Each sending cpu has a per-cpu mask which it fills from the caller's @@ -793,7 +853,6 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask, else return NULL; } - stat = &per_cpu(ptcstats, cpu); stat->s_requestor++; stat->s_ntargcpu += remotes; remotes = bau_uvhub_weight(&bau_desc->distribution); @@ -973,7 +1032,9 @@ static int uv_ptc_seq_show(struct seq_file *file, void *data) seq_printf(file, "sw_ack recv rtime all "); seq_printf(file, - "one mult none retry canc nocan reset rcan\n"); + "one mult none retry canc nocan reset rcan "); + seq_printf(file, + "disable enable\n"); } if (cpu < num_possible_cpus() && cpu_online(cpu)) { stat = &per_cpu(ptcstats, cpu); @@ -993,7 +1054,7 @@ static int uv_ptc_seq_show(struct seq_file *file, void *data) /* destination side statistics */ seq_printf(file, - "%lx %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld\n", + "%lx %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld ", uv_read_global_mmr64(uv_cpu_to_pnode(cpu), UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE), stat->d_requestee, cycles_2_us(stat->d_time), @@ -1001,6 +1062,8 @@ static int uv_ptc_seq_show(struct seq_file *file, void *data) stat->d_nomsg, stat->d_retries, stat->d_canceled, stat->d_nocanceled, stat->d_resets, stat->d_rcanceled); + seq_printf(file, "%ld %ld\n", + stat->s_bau_disabled, stat->s_bau_reenabled); } return 0; @@ -1112,6 +1175,10 @@ static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user, "reset: number of ipi-style reset requests processed\n"); printk(KERN_DEBUG "rcan: number messages canceled by reset requests\n"); + printk(KERN_DEBUG + "disable: number times use of the BAU was disabled\n"); + printk(KERN_DEBUG + "enable: number times use of the BAU was re-enabled\n"); } else if (input_arg == -1) { for_each_present_cpu(cpu) { stat = &per_cpu(ptcstats, cpu); @@ -1568,6 +1635,7 @@ static void uv_init_per_cpu(int nuvhubs) kfree(uvhub_descs); for_each_present_cpu(cpu) { bcp = &per_cpu(bau_control, cpu); + bcp->baudisabled = 0; /* time interval to catch a hardware stay-busy bug */ bcp->timeout_interval = microsec_2_cycles(2*timeout_us); bcp->max_bau_concurrent = max_bau_concurrent; @@ -1609,6 +1677,8 @@ static int __init uv_bau_init(void) uv_nshift = uv_hub_info->m_val; uv_mmask = (1UL << uv_hub_info->m_val) - 1; nuvhubs = uv_num_possible_blades(); + spin_lock_init(&disable_lock); + congested_cycles = microsec_2_cycles(congested_response_us); uv_init_per_cpu(nuvhubs); |