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: Sebastian 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: Thomas Gleixner <tglx@linutronix.de>
diff --git a/mm/zswap.c b/mm/zswap.c
index 275b22c..b13aa57 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -352,70 +352,28 @@
**********************************/
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;
- }
- 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;
+ dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
+ if (!dst) {
+ pr_err("can't allocate compressor buffer\n");
+ return -ENOMEM;
}
- return NOTIFY_OK;
-}
-
-static int zswap_cpu_dstmem_notifier(struct notifier_block *nb,
- unsigned long action, void *pcpu)
-{
- return __zswap_cpu_dstmem_notifier(action, (unsigned long)pcpu);
-}
-
-static struct notifier_block zswap_dstmem_notifier = {
- .notifier_call = zswap_cpu_dstmem_notifier,
-};
-
-static int __init zswap_cpu_dstmem_init(void)
-{
- unsigned long cpu;
-
- 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();
+ per_cpu(zswap_dstmem, cpu) = dst;
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)
+static int zswap_dstmem_dead(unsigned int cpu)
{
- unsigned long cpu;
+ u8 *dst;
- 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();
+ dst = per_cpu(zswap_dstmem, cpu);
+ kfree(dst);
+ per_cpu(zswap_dstmem, cpu) = NULL;
+
+ return 0;
}
static int __zswap_cpu_comp_notifier(struct zswap_pool *pool,
@@ -1238,6 +1196,7 @@
static int __init init_zswap(void)
{
struct zswap_pool *pool;
+ int ret;
zswap_init_started = true;
@@ -1246,7 +1205,9 @@
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 @@
return 0;
pool_fail:
- zswap_cpu_dstmem_destroy();
+ cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);
dstmem_fail:
zswap_entry_cache_destroy();
cache_fail: