x86, UV: Disable BAU on network congestion (50fb55ac) · Commits · 戴 / test

arch/x86/include/asm/uv/uv_bau.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@
		*/

		#define UV_ITEMS_PER_DESCRIPTOR 8
		/* the 'throttle' to prevent the hardware stay-busy bug */
		#define MAX_BAU_CONCURRENT 3
		#define UV_CPUS_PER_ACT_STATUS 32
		#define UV_ACT_STATUS_MASK 0x3
		@@ -338,6 +339,7 @@ struct bau_control {
		int timeout_tries;
		int ipi_attempts;
		int conseccompletes;
		int baudisabled;
		int set_bau_off;
		short cpu;
		short uvhub_cpu;
		@@ -389,6 +391,8 @@ struct ptc_stats {
		unsigned long s_busy; /* status stayed busy past s/w timer */
		unsigned long s_throttles; /* waits in throttle */
		unsigned long s_retry_messages; /* retry broadcasts */
		unsigned long s_bau_reenabled; /* for bau enable/disable */
		unsigned long s_bau_disabled; /* for bau enable/disable */
		/* destination statistics */
		unsigned long d_alltlb; /* times all tlb's on this cpu were flushed */
		unsigned long d_onetlb; /* times just one tlb on this cpu was flushed */

arch/x86/kernel/tlb_uv.c

+73 −3

Original line number	Diff line number	Diff line
		@@ -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);

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