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Date: Fri, 21 Jun 2013 11:25:34 -0500
From: Nathan Zimmer <nzimmer@....com>
To: unlisted-recipients:; (no To-header on input)
Cc: holt@....com, travis@....com, nzimmer@....com, rob@...dley.net,
tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
yinghai@...nel.org, akpm@...ux-foundation.org,
gregkh@...uxfoundation.org, x86@...nel.org,
linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [RFC 2/2] x86_64, mm: Reinsert the absent memory
The memory we set aside in the previous patch needs to be reinserted.
We start this process via late_initcall so we will have multiple cpus to do
the work.
Signed-off-by: Mike Travis <travis@....com>
Signed-off-by: Nathan Zimmer <nzimmer@....com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Yinghai Lu <yinghai@...nel.org>
---
arch/x86/kernel/e820.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++
drivers/base/memory.c | 83 +++++++++++++++++++++++++++++++
include/linux/memory.h | 5 ++
3 files changed, 217 insertions(+)
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 3752dc5..d31039d 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -23,6 +23,7 @@
#ifdef CONFIG_DELAY_MEM_INIT
#include <linux/memory.h>
+#include <linux/delay.h>
#endif
#include <asm/e820.h>
@@ -397,6 +398,22 @@ static u64 min_region_size; /* min size of region to slice from */
static u64 pre_region_size; /* multiply bsize for node low memory */
static u64 post_region_size; /* multiply bsize for node high memory */
+static unsigned long add_absent_work_start_time;
+static unsigned long add_absent_work_stop_time;
+static unsigned int add_absent_job_count;
+static atomic_t add_absent_work_count;
+
+struct absent_work {
+ struct work_struct work;
+ struct absent_work *next;
+ atomic_t busy;
+ int cpu;
+ int node;
+ int index;
+};
+static DEFINE_PER_CPU(struct absent_work, absent_work);
+static struct absent_work *first_absent_work;
+
static int __init setup_delay_mem_init(char *str)
{
int bbits, mpnbits, minmult, premult, postmult;
@@ -527,6 +544,118 @@ int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
}
return ret;
}
+
+/* Assign a cpu for this memory chunk and get the per_cpu absent_work struct */
+static struct absent_work *get_absent_work(int node)
+{
+ int cpu;
+
+ for_each_cpu(cpu, cpumask_of_node(node)) {
+ struct absent_work *aws = &per_cpu(absent_work, cpu);
+ if (aws->node)
+ continue;
+ aws->cpu = cpu;
+ aws->node = node;
+ return aws;
+ }
+
+ /* (if this becomes a problem, we can use a cpu on another node) */
+ pr_crit("e820: No CPU on Node %d to schedule absent_work\n", node);
+ return NULL;
+}
+
+/* Count of 'not done' processes */
+static int count_absent_work_notdone(void)
+{
+ struct absent_work *aws;
+ int notdone = 0;
+
+ for (aws = first_absent_work; aws; aws = aws->next)
+ if (atomic_read(&aws->busy) < 2)
+ notdone++;
+
+ return notdone;
+}
+
+/* The absent_work thread */
+static void add_absent_memory_work(struct work_struct *work)
+{
+ struct absent_work *aws;
+ u64 phys_addr, size;
+ int ret;
+
+ aws = container_of(work, struct absent_work, work);
+
+ phys_addr = e820_absent.map[aws->index].addr;
+ size = e820_absent.map[aws->index].size;
+ ret = memory_add_absent(aws->node, phys_addr, size);
+ if (ret)
+ pr_crit("e820: Error %d adding absent memory %llx %llx (%d)\n",
+ ret, phys_addr, size, aws->node);
+
+ atomic_set(&aws->busy, 2);
+ atomic_dec(&add_absent_work_count);
+
+ /* if no one is waiting, then snap stop time */
+ if (!count_absent_work_notdone())
+ add_absent_work_stop_time = get_seconds();
+}
+
+/* Initialize absent_work threads */
+static int add_absent_memory(void)
+{
+ struct absent_work *aws = NULL;
+ int cpu, i;
+
+ add_absent_work_start_time = get_seconds();
+ add_absent_work_stop_time = 0;
+ atomic_set(&add_absent_work_count, 0);
+
+ for_each_online_cpu(cpu) {
+ struct absent_work *aws = &per_cpu(absent_work, cpu);
+ aws->node = 0;
+ }
+
+ /* setup each work thread */
+ for (i = 0; i < e820_absent.nr_map; i++) {
+ u64 phys_addr = e820_absent.map[i].addr;
+ int node = memory_add_physaddr_to_nid(phys_addr);
+
+ if (!node_online(node))
+ continue;
+
+ if (!aws) {
+ aws = get_absent_work(node);
+ first_absent_work = aws;
+ } else {
+ aws->next = get_absent_work(node);
+ aws = aws->next;
+ }
+
+ if (!aws)
+ continue;
+
+ INIT_WORK(&aws->work, add_absent_memory_work);
+ atomic_set(&aws->busy, 0);
+ aws->index = i;
+
+ /* schedule absent_work thread */
+ if (!schedule_work_on(aws->cpu, &aws->work))
+ BUG();
+ }
+
+
+ pr_info("e820: Add absent memory started\n");
+
+ return 0;
+}
+
+/* Called during bootup to start adding absent_mem early */
+static int absent_memory_init(void)
+{
+ return add_absent_memory();
+}
+late_initcall(absent_memory_init);
#endif /* CONFIG_DELAY_MEM_INIT */
static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 14f8a69..5b4245a 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -442,6 +442,89 @@ static inline int memory_probe_init(void)
}
#endif
+#ifdef CONFIG_DELAY_MEM_INIT
+static struct memory_block *memory_get_block(u64 phys_addr,
+ struct memory_block *last_mem_blk)
+{
+ unsigned long pfn = phys_addr >> PAGE_SHIFT;
+ struct memory_block *mem_blk = NULL;
+ struct mem_section *mem_sect;
+ unsigned long section_nr = pfn_to_section_nr(pfn);
+
+ if (!present_section_nr(section_nr))
+ return NULL;
+
+ mem_sect = __nr_to_section(section_nr);
+ mem_blk = find_memory_block_hinted(mem_sect, last_mem_blk);
+ return mem_blk;
+}
+
+/* addr and size must be aligned on memory_block_size boundaries */
+int memory_add_absent(int nid, u64 phys_addr, u64 size)
+{
+ struct memory_block *mem = NULL;
+ struct page *first_page;
+ unsigned long block_sz;
+ unsigned long nr_pages;
+ unsigned long start_pfn;
+ int ret;
+
+ block_sz = get_memory_block_size();
+ if (phys_addr & (block_sz - 1) || size & (block_sz - 1))
+ return -EINVAL;
+
+ /* memory already present? */
+ if (memory_get_block(phys_addr, NULL))
+ return -EBUSY;
+
+ ret = add_memory(nid, phys_addr, size);
+ if (ret)
+ return ret;
+
+ /* grab first block to use for onlining process */
+ mem = memory_get_block(phys_addr, NULL);
+ if (!mem)
+ return -ENOMEM;
+
+ first_page = pfn_to_page(mem->start_section_nr << PFN_SECTION_SHIFT);
+ start_pfn = page_to_pfn(first_page);
+ nr_pages = size >> PAGE_SHIFT;
+
+ ret = online_pages(start_pfn, nr_pages, ONLINE_KEEP);
+ if (ret)
+ return ret;
+
+ for (;;) {
+ /* we already have first block from above */
+ mutex_lock(&mem->state_mutex);
+ if (mem->state == MEM_OFFLINE) {
+ mem->state = MEM_ONLINE;
+ kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE);
+ }
+ mutex_unlock(&mem->state_mutex);
+
+ phys_addr += block_sz;
+ size -= block_sz;
+ if (!size)
+ break;
+
+ mem = memory_get_block(phys_addr, mem);
+ if (mem)
+ continue;
+
+ pr_err("memory_get_block failed at %llx\n", phys_addr);
+ return -EFAULT;
+ }
+ return 0;
+}
+
+#else
+static inline int start_add_absent_init(void)
+{
+ return 0;
+}
+#endif /* CONFIG_DELAY_MEM_INIT */
+
#ifdef CONFIG_MEMORY_FAILURE
/*
* Support for offlining pages of memory
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 85c31a8..a000c54 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -128,6 +128,11 @@ extern struct memory_block *find_memory_block(struct mem_section *);
enum mem_add_context { BOOT, HOTPLUG };
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
+#ifdef CONFIG_DELAY_MEM_INIT
+extern int memory_add_absent(int nid, u64 phys_addr, u64 size);
+#endif
+
+
#ifdef CONFIG_MEMORY_HOTPLUG
#define hotplug_memory_notifier(fn, pri) ({ \
static __meminitdata struct notifier_block fn##_mem_nb =\
--
1.8.2.1
--
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