From ad7ed7708db9ff388450935645816d44bf08a56d Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Sun, 27 Nov 2016 00:13:39 +0100 Subject: 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 Cc: linux-mm@kvack.org Cc: Seth Jennings Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161126231350.10321-12-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/cpuhotplug.h | 1 + mm/zswap.c | 73 +++++++++++----------------------------------- 2 files changed, 18 insertions(+), 56 deletions(-) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 9f29dd996088..62f51a4e8676 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -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, diff --git a/mm/zswap.c b/mm/zswap.c index 275b22cc8df4..b13aa5706348 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -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; - } - 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; + per_cpu(zswap_dstmem, cpu) = dst; + 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: -- cgit v1.2.3