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x86, UV: BAU tunables into a debugfs file

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Make the Broadcast Assist Unit driver's nine tuning values variable by
making them accessible through a read/write debugfs file.

The file will normally be mounted as
/sys/kernel/debug/sgi_uv/bau_tunables. The tunables are kept in each
cpu's per-cpu BAU structure.

The patch also does a little name improvement, and corrects the reset of
two destination timeout counters.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNx-0004Zx-Uo@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Cliff Wickman 2010-06-02 16:22:01 -05:00 committed by Ingo Molnar
parent 12a6611fa1
commit e8e5e8a804
2 changed files with 281 additions and 59 deletions
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55
arch/x86/include/asm/uv/uv_bau.h
View File

@ -45,10 +45,14 @@
#define UV_DESC_BASE_PNODE_SHIFT 49
#define UV_PAYLOADQ_PNODE_SHIFT 49
#define UV_PTC_BASENAME "sgi_uv/ptc_statistics"
#define UV_BAU_BASENAME "sgi_uv/bau_tunables"
#define UV_BAU_TUNABLES_DIR "sgi_uv"
#define UV_BAU_TUNABLES_FILE "bau_tunables"
#define WHITESPACE " \t\n"
#define uv_physnodeaddr(x) ((__pa((unsigned long)(x)) & uv_mmask))
#define UV_ENABLE_INTD_SOFT_ACK_MODE_SHIFT 15
#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD_SHIFT 16
#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD 0x000000000bUL
#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD 0x0000000009UL
/* [19:16] SOFT_ACK timeout period 19: 1 is urgency 7 17:16 1 is multiplier */
#define BAU_MISC_CONTROL_MULT_MASK 3
@ -70,25 +74,23 @@
#define DESC_STATUS_DESTINATION_TIMEOUT 2
#define DESC_STATUS_SOURCE_TIMEOUT 3
/*
* source side threshholds at which message retries print a warning
*/
#define SOURCE_TIMEOUT_LIMIT 20
#define DESTINATION_TIMEOUT_LIMIT 20
/*
* misc. delays, in microseconds
*/
#define THROTTLE_DELAY 10
#define TIMEOUT_DELAY 10
#define BIOS_TO 1000
/* BIOS is assumed to set the destination timeout to 1003520 nanoseconds */
/*
* delay for 'plugged' timeout retries, in microseconds
*/
#define PLUGGED_DELAY 10
/*
* threshholds at which to use IPI to free resources
*/
/* after this # consecutive 'plugged' timeouts, use IPI to release resources */
#define PLUGSB4RESET 100
#define TIMEOUTSB4RESET 100
/* after this many consecutive timeouts, use IPI to release resources */
#define TIMEOUTSB4RESET 1
/* at this number uses of IPI to release resources, giveup the request */
#define IPI_RESET_LIMIT 1
/* after this # consecutive successes, bump up the throttle if it was lowered */
#define COMPLETE_THRESHOLD 5
/*
* number of entries in the destination side payload queue
@ -107,6 +109,13 @@
#define FLUSH_GIVEUP 3
#define FLUSH_COMPLETE 4
/*
* tuning the action when the numalink network is extremely delayed
*/
#define CONGESTED_RESPONSE_US 1000 /* 'long' response time, in microseconds */
#define CONGESTED_REPS 10 /* long delays averaged over this many broadcasts */
#define CONGESTED_PERIOD 30 /* time for the bau to be disabled, in seconds */
/*
* Distribution: 32 bytes (256 bits) (bytes 0-0x1f of descriptor)
* If the 'multilevel' flag in the header portion of the descriptor
@ -323,14 +332,13 @@ struct bau_control {
struct bau_control *uvhub_master;
struct bau_control *socket_master;
unsigned long timeout_interval;
unsigned long set_bau_on_time;
atomic_t active_descriptor_count;
int max_concurrent;
int max_concurrent_constant;
int retry_message_scans;
int plugged_tries;
int timeout_tries;
int ipi_attempts;
int conseccompletes;
int set_bau_off;
short cpu;
short uvhub_cpu;
short uvhub;
@ -343,6 +351,19 @@ struct bau_control {
spinlock_t masks_lock;
spinlock_t uvhub_lock;
spinlock_t queue_lock;
/* tunables */
int max_bau_concurrent;
int max_bau_concurrent_constant;
int plugged_delay;
int plugsb4reset;
int timeoutsb4reset;
int ipi_reset_limit;
int complete_threshold;
int congested_response_us;
int congested_reps;
int congested_period;
cycles_t period_time;
long period_requests;
};
/*

285
arch/x86/kernel/tlb_uv.c
View File

@ -8,6 +8,7 @@
*/
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/slab.h>
@ -42,12 +43,22 @@ static int timeout_base_ns[] = {
167772160
};
static int timeout_us;
#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD 0x000000000bUL
static int uv_bau_max_concurrent __read_mostly;
static int nobau;
/* tunables: */
static int max_bau_concurrent = MAX_BAU_CONCURRENT;
static int max_bau_concurrent_constant = MAX_BAU_CONCURRENT;
static int plugged_delay = PLUGGED_DELAY;
static int plugsb4reset = PLUGSB4RESET;
static int timeoutsb4reset = TIMEOUTSB4RESET;
static int ipi_reset_limit = IPI_RESET_LIMIT;
static int complete_threshold = COMPLETE_THRESHOLD;
static int congested_response_us = CONGESTED_RESPONSE_US;
static int congested_reps = CONGESTED_REPS;
static int congested_period = CONGESTED_PERIOD;
static struct dentry *tunables_dir;
static struct dentry *tunables_file;
static int __init setup_nobau(char *arg)
{
nobau = 1;
@ -539,23 +550,24 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc,
unsigned long index;
cycles_t time1;
cycles_t time2;
cycles_t elapsed;
struct ptc_stats *stat = &per_cpu(ptcstats, bcp->cpu);
struct bau_control *smaster = bcp->socket_master;
struct bau_control *hmaster = bcp->uvhub_master;
/*
* Spin here while there are hmaster->max_concurrent or more active
* Spin here while there are hmaster->max_bau_concurrent or more active
* descriptors. This is the per-uvhub 'throttle'.
*/
if (!atomic_inc_unless_ge(&hmaster->uvhub_lock,
&hmaster->active_descriptor_count,
hmaster->max_concurrent)) {
hmaster->max_bau_concurrent)) {
stat->s_throttles++;
do {
cpu_relax();
} while (!atomic_inc_unless_ge(&hmaster->uvhub_lock,
&hmaster->active_descriptor_count,
hmaster->max_concurrent));
hmaster->max_bau_concurrent));
}
while (hmaster->uvhub_quiesce)
@ -609,9 +621,9 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc,
* that case hardware immediately returns the ERROR
* that looks like a destination timeout.
*/
udelay(TIMEOUT_DELAY);
udelay(bcp->plugged_delay);
bcp->plugged_tries++;
if (bcp->plugged_tries >= PLUGSB4RESET) {
if (bcp->plugged_tries >= bcp->plugsb4reset) {
bcp->plugged_tries = 0;
quiesce_local_uvhub(hmaster);
spin_lock(&hmaster->queue_lock);
@ -623,10 +635,10 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc,
stat->s_resets_plug++;
}
} else if (completion_status == FLUSH_RETRY_TIMEOUT) {
hmaster->max_concurrent = 1;
hmaster->max_bau_concurrent = 1;
bcp->timeout_tries++;
udelay(TIMEOUT_DELAY);
if (bcp->timeout_tries >= TIMEOUTSB4RESET) {
if (bcp->timeout_tries >= bcp->timeoutsb4reset) {
bcp->timeout_tries = 0;
quiesce_local_uvhub(hmaster);
spin_lock(&hmaster->queue_lock);
@ -638,7 +650,7 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc,
stat->s_resets_timeout++;
}
}
if (bcp->ipi_attempts >= 3) {
if (bcp->ipi_attempts >= bcp->ipi_reset_limit) {
bcp->ipi_attempts = 0;
completion_status = FLUSH_GIVEUP;
break;
@ -648,9 +660,14 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc,
(completion_status == FLUSH_RETRY_TIMEOUT));
time2 = get_cycles();
if ((completion_status == FLUSH_COMPLETE) && (bcp->conseccompletes > 5)
&& (hmaster->max_concurrent < hmaster->max_concurrent_constant))
hmaster->max_concurrent++;
bcp->plugged_tries = 0;
bcp->timeout_tries = 0;
if ((completion_status == FLUSH_COMPLETE) &&
(bcp->conseccompletes > bcp->complete_threshold) &&
(hmaster->max_bau_concurrent <
hmaster->max_bau_concurrent_constant))
hmaster->max_bau_concurrent++;
/*
* hold any cpu not timing out here; no other cpu currently held by
@ -661,9 +678,10 @@ const struct cpumask *uv_flush_send_and_wait(struct bau_desc *bau_desc,
atomic_dec(&hmaster->active_descriptor_count);
/* guard against cycles wrap */
if (time2 > time1)
stat->s_time += (time2 - time1);
else
if (time2 > time1) {
elapsed = time2 - time1;
stat->s_time += elapsed;
} else
stat->s_requestor--; /* don't count this one */
if (completion_status == FLUSH_COMPLETE && try > 1)
stat->s_retriesok++;
@ -730,10 +748,12 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct ptc_stats *stat;
struct bau_control *bcp;
/* kernel was booted 'nobau' */
if (nobau)
return cpumask;
bcp = &per_cpu(bau_control, cpu);
/*
* Each sending cpu has a per-cpu mask which it fills from the caller's
* cpu mask. Only remote cpus are converted to uvhubs and copied.
@ -970,6 +990,7 @@ static int uv_ptc_seq_show(struct seq_file *file, void *data)
stat->s_resets_plug, stat->s_resets_timeout,
stat->s_giveup, stat->s_stimeout,
stat->s_busy, stat->s_throttles);
/* destination side statistics */
seq_printf(file,
"%lx %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld\n",
@ -985,10 +1006,29 @@ static int uv_ptc_seq_show(struct seq_file *file, void *data)
return 0;
}
/*
* Display the tunables thru debugfs
*/
static ssize_t tunables_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
char buf[300];
int ret;
ret = snprintf(buf, 300, "%s %s %s\n%d %d %d %d %d %d %d %d %d\n",
"max_bau_concurrent plugged_delay plugsb4reset",
"timeoutsb4reset ipi_reset_limit complete_threshold",
"congested_response_us congested_reps congested_period",
max_bau_concurrent, plugged_delay, plugsb4reset,
timeoutsb4reset, ipi_reset_limit, complete_threshold,
congested_response_us, congested_reps, congested_period);
return simple_read_from_buffer(userbuf, count, ppos, buf, ret);
}
/*
* -1: resetf the statistics
* 0: display meaning of the statistics
* >0: maximum concurrent active descriptors per uvhub (throttle)
*/
static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user,
size_t count, loff_t *data)
@ -997,7 +1037,6 @@ static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user,
long input_arg;
char optstr[64];
struct ptc_stats *stat;
struct bau_control *bcp;
if (count == 0 || count > sizeof(optstr))
return -EINVAL;
@ -1078,27 +1117,152 @@ static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user,
stat = &per_cpu(ptcstats, cpu);
memset(stat, 0, sizeof(struct ptc_stats));
}
} else {
uv_bau_max_concurrent = input_arg;
bcp = &per_cpu(bau_control, smp_processor_id());
if (uv_bau_max_concurrent < 1 ||
uv_bau_max_concurrent > bcp->cpus_in_uvhub) {
printk(KERN_DEBUG
"Error: BAU max concurrent %d; %d is invalid\n",
bcp->max_concurrent, uv_bau_max_concurrent);
return -EINVAL;
}
printk(KERN_DEBUG "Set BAU max concurrent:%d\n",
uv_bau_max_concurrent);
for_each_present_cpu(cpu) {
bcp = &per_cpu(bau_control, cpu);
bcp->max_concurrent = uv_bau_max_concurrent;
}
}
return count;
}
static int local_atoi(const char *name)
{
int val = 0;
for (;; name++) {
switch (*name) {
case '0' ... '9':
val = 10*val+(*name-'0');
break;
default:
return val;
}
}
}
/*
* set the tunables
* 0 values reset them to defaults
*/
static ssize_t tunables_write(struct file *file, const char __user *user,
size_t count, loff_t *data)
{
int cpu;
int cnt = 0;
int val;
char *p;
char *q;
char instr[64];
struct bau_control *bcp;
if (count == 0 || count > sizeof(instr)-1)
return -EINVAL;
if (copy_from_user(instr, user, count))
return -EFAULT;
instr[count] = '\0';
/* count the fields */
p = instr + strspn(instr, WHITESPACE);
q = p;
for (; *p; p = q + strspn(q, WHITESPACE)) {
q = p + strcspn(p, WHITESPACE);
cnt++;
if (q == p)
break;
}
if (cnt != 9) {
printk(KERN_INFO "bau tunable error: should be 9 numbers\n");
return -EINVAL;
}
p = instr + strspn(instr, WHITESPACE);
q = p;
for (cnt = 0; *p; p = q + strspn(q, WHITESPACE), cnt++) {
q = p + strcspn(p, WHITESPACE);
val = local_atoi(p);
switch (cnt) {
case 0:
if (val == 0) {
max_bau_concurrent = MAX_BAU_CONCURRENT;
max_bau_concurrent_constant =
MAX_BAU_CONCURRENT;
continue;
}
bcp = &per_cpu(bau_control, smp_processor_id());
if (val < 1 || val > bcp->cpus_in_uvhub) {
printk(KERN_DEBUG
"Error: BAU max concurrent %d is invalid\n",
val);
return -EINVAL;
}
max_bau_concurrent = val;
max_bau_concurrent_constant = val;
continue;
case 1:
if (val == 0)
plugged_delay = PLUGGED_DELAY;
else
plugged_delay = val;
continue;
case 2:
if (val == 0)
plugsb4reset = PLUGSB4RESET;
else
plugsb4reset = val;
continue;
case 3:
if (val == 0)
timeoutsb4reset = TIMEOUTSB4RESET;
else
timeoutsb4reset = val;
continue;
case 4:
if (val == 0)
ipi_reset_limit = IPI_RESET_LIMIT;
else
ipi_reset_limit = val;
continue;
case 5:
if (val == 0)
complete_threshold = COMPLETE_THRESHOLD;
else
complete_threshold = val;
continue;
case 6:
if (val == 0)
congested_response_us = CONGESTED_RESPONSE_US;
else
congested_response_us = val;
continue;
case 7:
if (val == 0)
congested_reps = CONGESTED_REPS;
else
congested_reps = val;
continue;
case 8:
if (val == 0)
congested_period = CONGESTED_PERIOD;
else
congested_period = val;
continue;
}
if (q == p)
break;
}
for_each_present_cpu(cpu) {
bcp = &per_cpu(bau_control, cpu);
bcp->max_bau_concurrent = max_bau_concurrent;
bcp->max_bau_concurrent_constant = max_bau_concurrent;
bcp->plugged_delay = plugged_delay;
bcp->plugsb4reset = plugsb4reset;
bcp->timeoutsb4reset = timeoutsb4reset;
bcp->ipi_reset_limit = ipi_reset_limit;
bcp->complete_threshold = complete_threshold;
bcp->congested_response_us = congested_response_us;
bcp->congested_reps = congested_reps;
bcp->congested_period = congested_period;
}
return count;
}
static const struct seq_operations uv_ptc_seq_ops = {
.start = uv_ptc_seq_start,
.next = uv_ptc_seq_next,
@ -1111,6 +1275,11 @@ static int uv_ptc_proc_open(struct inode *inode, struct file *file)
return seq_open(file, &uv_ptc_seq_ops);
}
static int tunables_open(struct inode *inode, struct file *file)
{
return 0;
}
static const struct file_operations proc_uv_ptc_operations = {
.open = uv_ptc_proc_open,
.read = seq_read,
@ -1119,6 +1288,12 @@ static const struct file_operations proc_uv_ptc_operations = {
.release = seq_release,
};
static const struct file_operations tunables_fops = {
.open = tunables_open,
.read = tunables_read,
.write = tunables_write,
};
static int __init uv_ptc_init(void)
{
struct proc_dir_entry *proc_uv_ptc;
@ -1133,6 +1308,20 @@ static int __init uv_ptc_init(void)
UV_PTC_BASENAME);
return -EINVAL;
}
tunables_dir = debugfs_create_dir(UV_BAU_TUNABLES_DIR, NULL);
if (!tunables_dir) {
printk(KERN_ERR "unable to create debugfs directory %s\n",
UV_BAU_TUNABLES_DIR);
return -EINVAL;
}
tunables_file = debugfs_create_file(UV_BAU_TUNABLES_FILE, 0600,
tunables_dir, NULL, &tunables_fops);
if (!tunables_file) {
printk(KERN_ERR "unable to create debugfs file %s\n",
UV_BAU_TUNABLES_FILE);
return -EINVAL;
}
return 0;
}
@ -1336,15 +1525,12 @@ static void uv_init_per_cpu(int nuvhubs)
bcp = &per_cpu(bau_control, cpu);
memset(bcp, 0, sizeof(struct bau_control));
spin_lock_init(&bcp->masks_lock);
bcp->max_concurrent = uv_bau_max_concurrent;
pnode = uv_cpu_hub_info(cpu)->pnode;
uvhub = uv_cpu_hub_info(cpu)->numa_blade_id;
bdp = &uvhub_descs[uvhub];
bdp->num_cpus++;
bdp->uvhub = uvhub;
bdp->pnode = pnode;
/* time interval to catch a hardware stay-busy bug */
bcp->timeout_interval = microsec_2_cycles(2*timeout_us);
/* kludge: assume uv_hub.h is constant */
socket = (cpu_physical_id(cpu)>>5)&1;
if (socket >= bdp->num_sockets)
@ -1380,6 +1566,21 @@ static void uv_init_per_cpu(int nuvhubs)
}
}
kfree(uvhub_descs);
for_each_present_cpu(cpu) {
bcp = &per_cpu(bau_control, cpu);
/* 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;
bcp->max_bau_concurrent_constant = max_bau_concurrent;
bcp->plugged_delay = plugged_delay;
bcp->plugsb4reset = plugsb4reset;
bcp->timeoutsb4reset = timeoutsb4reset;
bcp->ipi_reset_limit = ipi_reset_limit;
bcp->complete_threshold = complete_threshold;
bcp->congested_response_us = congested_response_us;
bcp->congested_reps = congested_reps;
bcp->congested_period = congested_period;
}
}
/*
@ -1404,7 +1605,7 @@ static int __init uv_bau_init(void)
zalloc_cpumask_var_node(&per_cpu(uv_flush_tlb_mask, cur_cpu),
GFP_KERNEL, cpu_to_node(cur_cpu));
uv_bau_max_concurrent = MAX_BAU_CONCURRENT;
max_bau_concurrent = MAX_BAU_CONCURRENT;
uv_nshift = uv_hub_info->m_val;
uv_mmask = (1UL << uv_hub_info->m_val) - 1;
nuvhubs = uv_num_possible_blades();
@ -1437,4 +1638,4 @@ static int __init uv_bau_init(void)
return 0;
}
core_initcall(uv_bau_init);
core_initcall(uv_ptc_init);
fs_initcall(uv_ptc_init);