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Date: Sun, 27 Nov 2016 00:13:46 +0100
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: linux-kernel@...r.kernel.org
Cc: rt@...utronix.de, tglx@...utronix.de,
Anna-Maria Gleixner <anna-maria@...utronix.de>,
Minchan Kim <minchan@...nel.org>,
Nitin Gupta <ngupta@...are.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Subject: [PATCH 18/22] zram: Convert to hotplug state machine
From: Anna-Maria Gleixner <anna-maria@...utronix.de>
Install the callbacks via the state machine with multi instance support and let
the core invoke the callbacks on the already online CPUs.
Cc: Minchan Kim <minchan@...nel.org>
Cc: Nitin Gupta <ngupta@...are.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
[bigeasy: wire up the multi instance stuff]
Signed-off-by: Anna-Maria Gleixner <anna-maria@...utronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
drivers/block/zram/zcomp.c | 76 ++++++++++++++-----------------------------
drivers/block/zram/zcomp.h | 5 +--
drivers/block/zram/zram_drv.c | 9 +++++
include/linux/cpuhotplug.h | 1 +
4 files changed, 38 insertions(+), 53 deletions(-)
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 4b5cd3a7b2b6..12046f4f00e4 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -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);
}
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 478cac2ed465..41c1002a7d7d 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -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);
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 04365b17ee67..511c35fd5c6f 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -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;
}
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 71c6822dd5be..22acee76cf4c 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -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,
--
2.10.2
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