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zram: Convert to hotplug state machine

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Install the callbacks via the state machine with multi instance support and let
the core invoke the callbacks on the already online CPUs.

[bigeasy: wire up the multi instance stuff]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: rt@linutronix.de
Cc: Nitin Gupta <ngupta@vflare.org>
Link: http://lkml.kernel.org/r/20161126231350.10321-19-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Anna-Maria Gleixner 2016-11-27 00:13:46 +01:00 committed by Thomas Gleixner
parent 3f7cd919f3
commit 1dd6c834fa
4 changed files with 38 additions and 53 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
drivers/block/zram/zcomp.c
View File

@ -160,82 +160,56 @@ int zcomp_decompress(struct zcomp_strm *zstrm,
dst, &dst_len);
}
static int __zcomp_cpu_notifier(struct zcomp *comp,
unsigned long action, unsigned long cpu)
int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
{
struct zcomp *comp = hlist_entry(node, struct zcomp, node);
struct zcomp_strm *zstrm;
switch (action) {
case CPU_UP_PREPARE:
if (WARN_ON(*per_cpu_ptr(comp->stream, cpu)))
break;
zstrm = zcomp_strm_alloc(comp);
if (IS_ERR_OR_NULL(zstrm)) {
pr_err("Can't allocate a compression stream\n");
return NOTIFY_BAD;
}
*per_cpu_ptr(comp->stream, cpu) = zstrm;
break;
case CPU_DEAD:
case CPU_UP_CANCELED:
zstrm = *per_cpu_ptr(comp->stream, cpu);
if (!IS_ERR_OR_NULL(zstrm))
zcomp_strm_free(zstrm);
*per_cpu_ptr(comp->stream, cpu) = NULL;
break;
default:
break;
if (WARN_ON(*per_cpu_ptr(comp->stream, cpu)))
return 0;
zstrm = zcomp_strm_alloc(comp);
if (IS_ERR_OR_NULL(zstrm)) {
pr_err("Can't allocate a compression stream\n");
return -ENOMEM;
}
return NOTIFY_OK;
*per_cpu_ptr(comp->stream, cpu) = zstrm;
return 0;
}
static int zcomp_cpu_notifier(struct notifier_block *nb,
unsigned long action, void *pcpu)
int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node)
{
unsigned long cpu = (unsigned long)pcpu;
struct zcomp *comp = container_of(nb, typeof(*comp), notifier);
struct zcomp *comp = hlist_entry(node, struct zcomp, node);
struct zcomp_strm *zstrm;
return __zcomp_cpu_notifier(comp, action, cpu);
zstrm = *per_cpu_ptr(comp->stream, cpu);
if (!IS_ERR_OR_NULL(zstrm))
zcomp_strm_free(zstrm);
*per_cpu_ptr(comp->stream, cpu) = NULL;
return 0;
}
static int zcomp_init(struct zcomp *comp)
{
unsigned long cpu;
int ret;
comp->notifier.notifier_call = zcomp_cpu_notifier;
comp->stream = alloc_percpu(struct zcomp_strm *);
if (!comp->stream)
return -ENOMEM;
cpu_notifier_register_begin();
for_each_online_cpu(cpu) {
ret = __zcomp_cpu_notifier(comp, CPU_UP_PREPARE, cpu);
if (ret == NOTIFY_BAD)
goto cleanup;
}
__register_cpu_notifier(&comp->notifier);
cpu_notifier_register_done();
ret = cpuhp_state_add_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
if (ret < 0)
goto cleanup;
return 0;
cleanup:
for_each_online_cpu(cpu)
__zcomp_cpu_notifier(comp, CPU_UP_CANCELED, cpu);
cpu_notifier_register_done();
return -ENOMEM;
free_percpu(comp->stream);
return ret;
}
void zcomp_destroy(struct zcomp *comp)
{
unsigned long cpu;
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
__zcomp_cpu_notifier(comp, CPU_UP_CANCELED, cpu);
__unregister_cpu_notifier(&comp->notifier);
cpu_notifier_register_done();
cpuhp_state_remove_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
free_percpu(comp->stream);
kfree(comp);
}

5
drivers/block/zram/zcomp.h
View File

@ -19,11 +19,12 @@ struct zcomp_strm {
/* dynamic per-device compression frontend */
struct zcomp {
struct zcomp_strm * __percpu *stream;
struct notifier_block notifier;
const char *name;
struct hlist_node node;
};
int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node);
int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node);
ssize_t zcomp_available_show(const char *comp, char *buf);
bool zcomp_available_algorithm(const char *comp);

9
drivers/block/zram/zram_drv.c
View File

@ -30,6 +30,7 @@
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/sysfs.h>
#include <linux/cpuhotplug.h>
#include "zram_drv.h"
@ -1436,15 +1437,22 @@ static void destroy_devices(void)
idr_for_each(&zram_index_idr, &zram_remove_cb, NULL);
idr_destroy(&zram_index_idr);
unregister_blkdev(zram_major, "zram");
cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE);
}
static int __init zram_init(void)
{
int ret;
ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare",
zcomp_cpu_up_prepare, zcomp_cpu_dead);
if (ret < 0)
return ret;
ret = class_register(&zram_control_class);
if (ret) {
pr_err("Unable to register zram-control class\n");
cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE);
return ret;
}
@ -1452,6 +1460,7 @@ static int __init zram_init(void)
if (zram_major <= 0) {
pr_err("Unable to get major number\n");
class_unregister(&zram_control_class);
cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE);
return -EBUSY;
}

1
include/linux/cpuhotplug.h
View File

@ -69,6 +69,7 @@ enum cpuhp_state {
CPUHP_MM_ZSWP_MEM_PREPARE,
CPUHP_MM_ZSWP_POOL_PREPARE,
CPUHP_KVM_PPC_BOOK3S_PREPARE,
CPUHP_ZCOMP_PREPARE,
CPUHP_TIMERS_DEAD,
CPUHP_NOTF_ERR_INJ_PREPARE,
CPUHP_MIPS_SOC_PREPARE,