Commit ad7ed770 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
Browse files

mm/zswap: Convert dst-mem to hotplug state machine 



Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mm@kvack.org
Cc: Seth Jennings <sjenning@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161126231350.10321-12-bigeasy@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 215c89d0

include/linux/cpuhotplug.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ enum cpuhp_state { 
	CPUHP_ARM_BL_PREPARE,

	CPUHP_TRACE_RB_PREPARE,

	CPUHP_MM_ZS_PREPARE,

	CPUHP_MM_ZSWP_MEM_PREPARE,

	CPUHP_TIMERS_DEAD,

	CPUHP_NOTF_ERR_INJ_PREPARE,

	CPUHP_MIPS_SOC_PREPARE,

mm/zswap.c

+17 −56
Original line number Diff line number Diff line
@@ -352,70 +352,28 @@ static struct zswap_entry *zswap_entry_find_get(struct rb_root *root, 
**********************************/

static DEFINE_PER_CPU(u8 *, zswap_dstmem);



static int __zswap_cpu_dstmem_notifier(unsigned long action, unsigned long cpu)

static int zswap_dstmem_prepare(unsigned int cpu)

{

	u8 *dst;



	switch (action) {

	case CPU_UP_PREPARE:

	dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));

	if (!dst) {

		pr_err("can't allocate compressor buffer\n");

			return NOTIFY_BAD;

		return -ENOMEM;

	}

	per_cpu(zswap_dstmem, cpu) = dst;

		break;

	case CPU_DEAD:

	case CPU_UP_CANCELED:

		dst = per_cpu(zswap_dstmem, cpu);

		kfree(dst);

		per_cpu(zswap_dstmem, cpu) = NULL;

		break;

	default:

		break;

	}

	return NOTIFY_OK;

	return 0;

}



static int zswap_cpu_dstmem_notifier(struct notifier_block *nb,

				     unsigned long action, void *pcpu)

static int zswap_dstmem_dead(unsigned int cpu)

{

	return __zswap_cpu_dstmem_notifier(action, (unsigned long)pcpu);

}



static struct notifier_block zswap_dstmem_notifier = {

	.notifier_call =	zswap_cpu_dstmem_notifier,

};

	u8 *dst;



static int __init zswap_cpu_dstmem_init(void)

{

	unsigned long cpu;

	dst = per_cpu(zswap_dstmem, cpu);

	kfree(dst);

	per_cpu(zswap_dstmem, cpu) = NULL;



	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)

		if (__zswap_cpu_dstmem_notifier(CPU_UP_PREPARE, cpu) ==

		    NOTIFY_BAD)

			goto cleanup;

	__register_cpu_notifier(&zswap_dstmem_notifier);

	cpu_notifier_register_done();

	return 0;



cleanup:

	for_each_online_cpu(cpu)

		__zswap_cpu_dstmem_notifier(CPU_UP_CANCELED, cpu);

	cpu_notifier_register_done();

	return -ENOMEM;

}



static void zswap_cpu_dstmem_destroy(void)

{

	unsigned long cpu;



	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)

		__zswap_cpu_dstmem_notifier(CPU_UP_CANCELED, cpu);

	__unregister_cpu_notifier(&zswap_dstmem_notifier);

	cpu_notifier_register_done();

}



static int __zswap_cpu_comp_notifier(struct zswap_pool *pool,
@@ -1238,6 +1196,7 @@ static void __exit zswap_debugfs_exit(void) { } 
static int __init init_zswap(void)

{

	struct zswap_pool *pool;

	int ret;



	zswap_init_started = true;
@@ -1246,7 +1205,9 @@ static int __init init_zswap(void) 
		goto cache_fail;

	}



	if (zswap_cpu_dstmem_init()) {

	ret = cpuhp_setup_state(CPUHP_MM_ZSWP_MEM_PREPARE, "mm/zswap:prepare",

				zswap_dstmem_prepare, zswap_dstmem_dead);

	if (ret) {

		pr_err("dstmem alloc failed\n");

		goto dstmem_fail;

	}
@@ -1267,7 +1228,7 @@ static int __init init_zswap(void) 
	return 0;



pool_fail:

	zswap_cpu_dstmem_destroy();

	cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);

dstmem_fail:

	zswap_entry_cache_destroy();

cache_fail:

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