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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 19:43:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 19:43:08 -0700
commit597f03f9d133e9837d00965016170271d4f87dcf (patch)
tree33bdb5c1104d5b466387f4ae98748c5f4ddd29bb /kernel/relay.c
parent999dcbe2414e15e19cdc1f91497d01f262c6e1cf (diff)
parent0bf71e4d02ffec8ab9a6adecca61d3eed74fc99d (diff)
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug updates from Thomas Gleixner: "Yet another batch of cpu hotplug core updates and conversions: - Provide core infrastructure for multi instance drivers so the drivers do not have to keep custom lists. - Convert custom lists to the new infrastructure. The block-mq custom list conversion comes through the block tree and makes the diffstat tip over to more lines removed than added. - Handle unbalanced hotplug enable/disable calls more gracefully. - Remove the obsolete CPU_STARTING/DYING notifier support. - Convert another batch of notifier users. The relayfs changes which conflicted with the conversion have been shipped to me by Andrew. The remaining lot is targeted for 4.10 so that we finally can remove the rest of the notifiers" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) cpufreq: Fix up conversion to hotplug state machine blk/mq: Reserve hotplug states for block multiqueue x86/apic/uv: Convert to hotplug state machine s390/mm/pfault: Convert to hotplug state machine mips/loongson/smp: Convert to hotplug state machine mips/octeon/smp: Convert to hotplug state machine fault-injection/cpu: Convert to hotplug state machine padata: Convert to hotplug state machine cpufreq: Convert to hotplug state machine ACPI/processor: Convert to hotplug state machine virtio scsi: Convert to hotplug state machine oprofile/timer: Convert to hotplug state machine block/softirq: Convert to hotplug state machine lib/irq_poll: Convert to hotplug state machine x86/microcode: Convert to hotplug state machine sh/SH-X3 SMP: Convert to hotplug state machine ia64/mca: Convert to hotplug state machine ARM/OMAP/wakeupgen: Convert to hotplug state machine ARM/shmobile: Convert to hotplug state machine arm64/FP/SIMD: Convert to hotplug state machine ...
Diffstat (limited to 'kernel/relay.c')
-rw-r--r--kernel/relay.c124
1 files changed, 51 insertions, 73 deletions
diff --git a/kernel/relay.c b/kernel/relay.c
index d797502140b9..fc9b4a4af463 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -214,7 +214,7 @@ static void relay_destroy_buf(struct rchan_buf *buf)
__free_page(buf->page_array[i]);
relay_free_page_array(buf->page_array);
}
- chan->buf[buf->cpu] = NULL;
+ *per_cpu_ptr(chan->buf, buf->cpu) = NULL;
kfree(buf->padding);
kfree(buf);
kref_put(&chan->kref, relay_destroy_channel);
@@ -382,20 +382,21 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init)
*/
void relay_reset(struct rchan *chan)
{
+ struct rchan_buf *buf;
unsigned int i;
if (!chan)
return;
- if (chan->is_global && chan->buf[0]) {
- __relay_reset(chan->buf[0], 0);
+ if (chan->is_global && (buf = *per_cpu_ptr(chan->buf, 0))) {
+ __relay_reset(buf, 0);
return;
}
mutex_lock(&relay_channels_mutex);
for_each_possible_cpu(i)
- if (chan->buf[i])
- __relay_reset(chan->buf[i], 0);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ __relay_reset(buf, 0);
mutex_unlock(&relay_channels_mutex);
}
EXPORT_SYMBOL_GPL(relay_reset);
@@ -440,7 +441,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
struct dentry *dentry;
if (chan->is_global)
- return chan->buf[0];
+ return *per_cpu_ptr(chan->buf, 0);
buf = relay_create_buf(chan);
if (!buf)
@@ -464,7 +465,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
__relay_reset(buf, 1);
if(chan->is_global) {
- chan->buf[0] = buf;
+ *per_cpu_ptr(chan->buf, 0) = buf;
buf->cpu = 0;
}
@@ -512,46 +513,25 @@ static void setup_callbacks(struct rchan *chan,
chan->cb = cb;
}
-/**
- * relay_hotcpu_callback - CPU hotplug callback
- * @nb: notifier block
- * @action: hotplug action to take
- * @hcpu: CPU number
- *
- * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
- */
-static int relay_hotcpu_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
+int relay_prepare_cpu(unsigned int cpu)
{
- unsigned int hotcpu = (unsigned long)hcpu;
struct rchan *chan;
+ struct rchan_buf *buf;
- switch(action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- mutex_lock(&relay_channels_mutex);
- list_for_each_entry(chan, &relay_channels, list) {
- if (chan->buf[hotcpu])
- continue;
- chan->buf[hotcpu] = relay_open_buf(chan, hotcpu);
- if(!chan->buf[hotcpu]) {
- printk(KERN_ERR
- "relay_hotcpu_callback: cpu %d buffer "
- "creation failed\n", hotcpu);
- mutex_unlock(&relay_channels_mutex);
- return notifier_from_errno(-ENOMEM);
- }
+ mutex_lock(&relay_channels_mutex);
+ list_for_each_entry(chan, &relay_channels, list) {
+ if ((buf = *per_cpu_ptr(chan->buf, cpu)))
+ continue;
+ buf = relay_open_buf(chan, cpu);
+ if (!buf) {
+ pr_err("relay: cpu %d buffer creation failed\n", cpu);
+ mutex_unlock(&relay_channels_mutex);
+ return -ENOMEM;
}
- mutex_unlock(&relay_channels_mutex);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- /* No need to flush the cpu : will be flushed upon
- * final relay_flush() call. */
- break;
+ *per_cpu_ptr(chan->buf, cpu) = buf;
}
- return NOTIFY_OK;
+ mutex_unlock(&relay_channels_mutex);
+ return 0;
}
/**
@@ -583,6 +563,7 @@ struct rchan *relay_open(const char *base_filename,
{
unsigned int i;
struct rchan *chan;
+ struct rchan_buf *buf;
if (!(subbuf_size && n_subbufs))
return NULL;
@@ -593,6 +574,7 @@ struct rchan *relay_open(const char *base_filename,
if (!chan)
return NULL;
+ chan->buf = alloc_percpu(struct rchan_buf *);
chan->version = RELAYFS_CHANNEL_VERSION;
chan->n_subbufs = n_subbufs;
chan->subbuf_size = subbuf_size;
@@ -608,9 +590,10 @@ struct rchan *relay_open(const char *base_filename,
mutex_lock(&relay_channels_mutex);
for_each_online_cpu(i) {
- chan->buf[i] = relay_open_buf(chan, i);
- if (!chan->buf[i])
+ buf = relay_open_buf(chan, i);
+ if (!buf)
goto free_bufs;
+ *per_cpu_ptr(chan->buf, i) = buf;
}
list_add(&chan->list, &relay_channels);
mutex_unlock(&relay_channels_mutex);
@@ -619,8 +602,8 @@ struct rchan *relay_open(const char *base_filename,
free_bufs:
for_each_possible_cpu(i) {
- if (chan->buf[i])
- relay_close_buf(chan->buf[i]);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ relay_close_buf(buf);
}
kref_put(&chan->kref, relay_destroy_channel);
@@ -666,6 +649,7 @@ int relay_late_setup_files(struct rchan *chan,
unsigned int i, curr_cpu;
unsigned long flags;
struct dentry *dentry;
+ struct rchan_buf *buf;
struct rchan_percpu_buf_dispatcher disp;
if (!chan || !base_filename)
@@ -684,10 +668,11 @@ int relay_late_setup_files(struct rchan *chan,
if (chan->is_global) {
err = -EINVAL;
- if (!WARN_ON_ONCE(!chan->buf[0])) {
- dentry = relay_create_buf_file(chan, chan->buf[0], 0);
+ buf = *per_cpu_ptr(chan->buf, 0);
+ if (!WARN_ON_ONCE(!buf)) {
+ dentry = relay_create_buf_file(chan, buf, 0);
if (dentry && !WARN_ON_ONCE(!chan->is_global)) {
- relay_set_buf_dentry(chan->buf[0], dentry);
+ relay_set_buf_dentry(buf, dentry);
err = 0;
}
}
@@ -702,13 +687,14 @@ int relay_late_setup_files(struct rchan *chan,
* on all currently online CPUs.
*/
for_each_online_cpu(i) {
- if (unlikely(!chan->buf[i])) {
+ buf = *per_cpu_ptr(chan->buf, i);
+ if (unlikely(!buf)) {
WARN_ONCE(1, KERN_ERR "CPU has no buffer!\n");
err = -EINVAL;
break;
}
- dentry = relay_create_buf_file(chan, chan->buf[i], i);
+ dentry = relay_create_buf_file(chan, buf, i);
if (unlikely(!dentry)) {
err = -EINVAL;
break;
@@ -716,10 +702,10 @@ int relay_late_setup_files(struct rchan *chan,
if (curr_cpu == i) {
local_irq_save(flags);
- relay_set_buf_dentry(chan->buf[i], dentry);
+ relay_set_buf_dentry(buf, dentry);
local_irq_restore(flags);
} else {
- disp.buf = chan->buf[i];
+ disp.buf = buf;
disp.dentry = dentry;
smp_mb();
/* relay_channels_mutex must be held, so wait. */
@@ -822,11 +808,10 @@ void relay_subbufs_consumed(struct rchan *chan,
if (!chan)
return;
- if (cpu >= NR_CPUS || !chan->buf[cpu] ||
- subbufs_consumed > chan->n_subbufs)
+ buf = *per_cpu_ptr(chan->buf, cpu);
+ if (cpu >= NR_CPUS || !buf || subbufs_consumed > chan->n_subbufs)
return;
- buf = chan->buf[cpu];
if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed)
buf->subbufs_consumed = buf->subbufs_produced;
else
@@ -842,18 +827,19 @@ EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
*/
void relay_close(struct rchan *chan)
{
+ struct rchan_buf *buf;
unsigned int i;
if (!chan)
return;
mutex_lock(&relay_channels_mutex);
- if (chan->is_global && chan->buf[0])
- relay_close_buf(chan->buf[0]);
+ if (chan->is_global && (buf = *per_cpu_ptr(chan->buf, 0)))
+ relay_close_buf(buf);
else
for_each_possible_cpu(i)
- if (chan->buf[i])
- relay_close_buf(chan->buf[i]);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ relay_close_buf(buf);
if (chan->last_toobig)
printk(KERN_WARNING "relay: one or more items not logged "
@@ -874,20 +860,21 @@ EXPORT_SYMBOL_GPL(relay_close);
*/
void relay_flush(struct rchan *chan)
{
+ struct rchan_buf *buf;
unsigned int i;
if (!chan)
return;
- if (chan->is_global && chan->buf[0]) {
- relay_switch_subbuf(chan->buf[0], 0);
+ if (chan->is_global && (buf = *per_cpu_ptr(chan->buf, 0))) {
+ relay_switch_subbuf(buf, 0);
return;
}
mutex_lock(&relay_channels_mutex);
for_each_possible_cpu(i)
- if (chan->buf[i])
- relay_switch_subbuf(chan->buf[i], 0);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ relay_switch_subbuf(buf, 0);
mutex_unlock(&relay_channels_mutex);
}
EXPORT_SYMBOL_GPL(relay_flush);
@@ -1377,12 +1364,3 @@ const struct file_operations relay_file_operations = {
.splice_read = relay_file_splice_read,
};
EXPORT_SYMBOL_GPL(relay_file_operations);
-
-static __init int relay_init(void)
-{
-
- hotcpu_notifier(relay_hotcpu_callback, 0);
- return 0;
-}
-
-early_initcall(relay_init);
generated by cgit v1.2.3 (git 2.0.4) at 2025-04-11 15:27:15 +0000