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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-01 19:19:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-01 19:19:15 -0700
commit7a48837732f87a574ee3e1855927dc250117f565 (patch)
treef2e975a347d6d489e9f1932f9864fc978910def0 /kernel
parent1a0b6abaea78f73d9bc0a2f6df2d9e4c917cade1 (diff)
parent27fbf4e87c16bb3e40730890169a643a494b7c64 (diff)
downloadlinux-7a48837732f87a574ee3e1855927dc250117f565.tar.gz
Merge branch 'for-3.15/core' of git://git.kernel.dk/linux-block
Pull core block layer updates from Jens Axboe: "This is the pull request for the core block IO bits for the 3.15 kernel. It's a smaller round this time, it contains: - Various little blk-mq fixes and additions from Christoph and myself. - Cleanup of the IPI usage from the block layer, and associated helper code. From Frederic Weisbecker and Jan Kara. - Duplicate code cleanup in bio-integrity from Gu Zheng. This will give you a merge conflict, but that should be easy to resolve. - blk-mq notify spinlock fix for RT from Mike Galbraith. - A blktrace partial accounting bug fix from Roman Pen. - Missing REQ_SYNC detection fix for blk-mq from Shaohua Li" * 'for-3.15/core' of git://git.kernel.dk/linux-block: (25 commits) blk-mq: add REQ_SYNC early rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock blk-mq: support partial I/O completions blk-mq: merge blk_mq_insert_request and blk_mq_run_request blk-mq: remove blk_mq_alloc_rq blk-mq: don't dump CPU -> hw queue map on driver load blk-mq: fix wrong usage of hctx->state vs hctx->flags blk-mq: allow blk_mq_init_commands() to return failure block: remove old blk_iopoll_enabled variable blktrace: fix accounting of partially completed requests smp: Rename __smp_call_function_single() to smp_call_function_single_async() smp: Remove wait argument from __smp_call_function_single() watchdog: Simplify a little the IPI call smp: Move __smp_call_function_single() below its safe version smp: Consolidate the various smp_call_function_single() declensions smp: Teach __smp_call_function_single() to check for offline cpus smp: Remove unused list_head from csd smp: Iterate functions through llist_for_each_entry_safe() block: Stop abusing rq->csd.list in blk-softirq block: Remove useless IPI struct initialization ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/core.c2
-rw-r--r--kernel/smp.c139
-rw-r--r--kernel/sysctl.c12
-rw-r--r--kernel/trace/blktrace.c20
-rw-r--r--kernel/up.c6
-rw-r--r--kernel/watchdog.c3
6 files changed, 81 insertions, 101 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3c4d096544c..9cae286824b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -432,7 +432,7 @@ void hrtick_start(struct rq *rq, u64 delay)
if (rq == this_rq()) {
__hrtick_restart(rq);
} else if (!rq->hrtick_csd_pending) {
- __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0);
+ smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd);
rq->hrtick_csd_pending = 1;
}
}
diff --git a/kernel/smp.c b/kernel/smp.c
index ffee35bef17..06d574e42c7 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -117,13 +117,43 @@ static void csd_unlock(struct call_single_data *csd)
csd->flags &= ~CSD_FLAG_LOCK;
}
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_data, csd_data);
+
/*
* Insert a previously allocated call_single_data element
* for execution on the given CPU. data must already have
* ->func, ->info, and ->flags set.
*/
-static void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
+static int generic_exec_single(int cpu, struct call_single_data *csd,
+ smp_call_func_t func, void *info, int wait)
{
+ struct call_single_data csd_stack = { .flags = 0 };
+ unsigned long flags;
+
+
+ if (cpu == smp_processor_id()) {
+ local_irq_save(flags);
+ func(info);
+ local_irq_restore(flags);
+ return 0;
+ }
+
+
+ if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu))
+ return -ENXIO;
+
+
+ if (!csd) {
+ csd = &csd_stack;
+ if (!wait)
+ csd = &__get_cpu_var(csd_data);
+ }
+
+ csd_lock(csd);
+
+ csd->func = func;
+ csd->info = info;
+
if (wait)
csd->flags |= CSD_FLAG_WAIT;
@@ -143,6 +173,8 @@ static void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
if (wait)
csd_lock_wait(csd);
+
+ return 0;
}
/*
@@ -151,7 +183,8 @@ static void generic_exec_single(int cpu, struct call_single_data *csd, int wait)
*/
void generic_smp_call_function_single_interrupt(void)
{
- struct llist_node *entry, *next;
+ struct llist_node *entry;
+ struct call_single_data *csd, *csd_next;
/*
* Shouldn't receive this interrupt on a cpu that is not yet online.
@@ -161,21 +194,12 @@ void generic_smp_call_function_single_interrupt(void)
entry = llist_del_all(&__get_cpu_var(call_single_queue));
entry = llist_reverse_order(entry);
- while (entry) {
- struct call_single_data *csd;
-
- next = entry->next;
-
- csd = llist_entry(entry, struct call_single_data, llist);
+ llist_for_each_entry_safe(csd, csd_next, entry, llist) {
csd->func(csd->info);
csd_unlock(csd);
-
- entry = next;
}
}
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_data, csd_data);
-
/*
* smp_call_function_single - Run a function on a specific CPU
* @func: The function to run. This must be fast and non-blocking.
@@ -187,12 +211,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_data, csd_data);
int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
int wait)
{
- struct call_single_data d = {
- .flags = 0,
- };
- unsigned long flags;
int this_cpu;
- int err = 0;
+ int err;
/*
* prevent preemption and reschedule on another processor,
@@ -209,32 +229,41 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
&& !oops_in_progress);
- if (cpu == this_cpu) {
- local_irq_save(flags);
- func(info);
- local_irq_restore(flags);
- } else {
- if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
- struct call_single_data *csd = &d;
+ err = generic_exec_single(cpu, NULL, func, info, wait);
- if (!wait)
- csd = &__get_cpu_var(csd_data);
+ put_cpu();
- csd_lock(csd);
+ return err;
+}
+EXPORT_SYMBOL(smp_call_function_single);
- csd->func = func;
- csd->info = info;
- generic_exec_single(cpu, csd, wait);
- } else {
- err = -ENXIO; /* CPU not online */
- }
- }
+/**
+ * smp_call_function_single_async(): Run an asynchronous function on a
+ * specific CPU.
+ * @cpu: The CPU to run on.
+ * @csd: Pre-allocated and setup data structure
+ *
+ * Like smp_call_function_single(), but the call is asynchonous and
+ * can thus be done from contexts with disabled interrupts.
+ *
+ * The caller passes his own pre-allocated data structure
+ * (ie: embedded in an object) and is responsible for synchronizing it
+ * such that the IPIs performed on the @csd are strictly serialized.
+ *
+ * NOTE: Be careful, there is unfortunately no current debugging facility to
+ * validate the correctness of this serialization.
+ */
+int smp_call_function_single_async(int cpu, struct call_single_data *csd)
+{
+ int err = 0;
- put_cpu();
+ preempt_disable();
+ err = generic_exec_single(cpu, csd, csd->func, csd->info, 0);
+ preempt_enable();
return err;
}
-EXPORT_SYMBOL(smp_call_function_single);
+EXPORT_SYMBOL_GPL(smp_call_function_single_async);
/*
* smp_call_function_any - Run a function on any of the given cpus
@@ -280,44 +309,6 @@ call:
EXPORT_SYMBOL_GPL(smp_call_function_any);
/**
- * __smp_call_function_single(): Run a function on a specific CPU
- * @cpu: The CPU to run on.
- * @data: Pre-allocated and setup data structure
- * @wait: If true, wait until function has completed on specified CPU.
- *
- * Like smp_call_function_single(), but allow caller to pass in a
- * pre-allocated data structure. Useful for embedding @data inside
- * other structures, for instance.
- */
-void __smp_call_function_single(int cpu, struct call_single_data *csd,
- int wait)
-{
- unsigned int this_cpu;
- unsigned long flags;
-
- this_cpu = get_cpu();
- /*
- * Can deadlock when called with interrupts disabled.
- * We allow cpu's that are not yet online though, as no one else can
- * send smp call function interrupt to this cpu and as such deadlocks
- * can't happen.
- */
- WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
- && !oops_in_progress);
-
- if (cpu == this_cpu) {
- local_irq_save(flags);
- csd->func(csd->info);
- local_irq_restore(flags);
- } else {
- csd_lock(csd);
- generic_exec_single(cpu, csd, wait);
- }
- put_cpu();
-}
-EXPORT_SYMBOL_GPL(__smp_call_function_single);
-
-/**
* smp_call_function_many(): Run a function on a set of other CPUs.
* @mask: The set of cpus to run on (only runs on online subset).
* @func: The function to run. This must be fast and non-blocking.
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7754ff16f33..09d2e241360 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -112,9 +112,6 @@ extern int sysctl_nr_open_min, sysctl_nr_open_max;
#ifndef CONFIG_MMU
extern int sysctl_nr_trim_pages;
#endif
-#ifdef CONFIG_BLOCK
-extern int blk_iopoll_enabled;
-#endif
/* Constants used for minimum and maximum */
#ifdef CONFIG_LOCKUP_DETECTOR
@@ -1087,15 +1084,6 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec,
},
#endif
-#ifdef CONFIG_BLOCK
- {
- .procname = "blk_iopoll",
- .data = &blk_iopoll_enabled,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
-#endif
{ }
};
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index b418cb0d724..4f3a3c03ead 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -702,6 +702,7 @@ void blk_trace_shutdown(struct request_queue *q)
* blk_add_trace_rq - Add a trace for a request oriented action
* @q: queue the io is for
* @rq: the source request
+ * @nr_bytes: number of completed bytes
* @what: the action
*
* Description:
@@ -709,7 +710,7 @@ void blk_trace_shutdown(struct request_queue *q)
*
**/
static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
- u32 what)
+ unsigned int nr_bytes, u32 what)
{
struct blk_trace *bt = q->blk_trace;
@@ -718,11 +719,11 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
what |= BLK_TC_ACT(BLK_TC_PC);
- __blk_add_trace(bt, 0, blk_rq_bytes(rq), rq->cmd_flags,
+ __blk_add_trace(bt, 0, nr_bytes, rq->cmd_flags,
what, rq->errors, rq->cmd_len, rq->cmd);
} else {
what |= BLK_TC_ACT(BLK_TC_FS);
- __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
+ __blk_add_trace(bt, blk_rq_pos(rq), nr_bytes,
rq->cmd_flags, what, rq->errors, 0, NULL);
}
}
@@ -730,33 +731,34 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
static void blk_add_trace_rq_abort(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_ABORT);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ABORT);
}
static void blk_add_trace_rq_insert(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_INSERT);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
}
static void blk_add_trace_rq_issue(void *ignore,
struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
}
static void blk_add_trace_rq_requeue(void *ignore,
struct request_queue *q,
struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
+ blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
}
static void blk_add_trace_rq_complete(void *ignore,
struct request_queue *q,
- struct request *rq)
+ struct request *rq,
+ unsigned int nr_bytes)
{
- blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
+ blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
}
/**
diff --git a/kernel/up.c b/kernel/up.c
index 509403e3fbc..1760bf3d146 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -22,16 +22,16 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
}
EXPORT_SYMBOL(smp_call_function_single);
-void __smp_call_function_single(int cpu, struct call_single_data *csd,
- int wait)
+int smp_call_function_single_async(int cpu, struct call_single_data *csd)
{
unsigned long flags;
local_irq_save(flags);
csd->func(csd->info);
local_irq_restore(flags);
+ return 0;
}
-EXPORT_SYMBOL(__smp_call_function_single);
+EXPORT_SYMBOL(smp_call_function_single_async);
int on_each_cpu(smp_call_func_t func, void *info, int wait)
{
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 4431610f049..01c6f979486 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -505,7 +505,6 @@ static void restart_watchdog_hrtimer(void *info)
static void update_timers(int cpu)
{
- struct call_single_data data = {.func = restart_watchdog_hrtimer};
/*
* Make sure that perf event counter will adopt to a new
* sampling period. Updating the sampling period directly would
@@ -515,7 +514,7 @@ static void update_timers(int cpu)
* might be late already so we have to restart the timer as well.
*/
watchdog_nmi_disable(cpu);
- __smp_call_function_single(cpu, &data, 1);
+ smp_call_function_single(cpu, restart_watchdog_hrtimer, NULL, 1);
watchdog_nmi_enable(cpu);
}