From: Peter Zijlstra <[email protected]>
Adds a refault histogram on top of the nonresident code.
Based on ideas and code from Rik van Riel.
Signed-off-by: Peter Zijlstra <[email protected]
fs/proc/proc_misc.c | 23 ++++++++++
mm/Kconfig | 5 ++
mm/Makefile | 1
mm/nonresident.c | 15 +++++-
mm/refault.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 155 insertions(+), 3 deletions(-)
Index: linux-2.6/fs/proc/proc_misc.c
===================================================================
--- linux-2.6.orig/fs/proc/proc_misc.c 2006-07-11 18:06:58.000000000 +0200
+++ linux-2.6/fs/proc/proc_misc.c 2006-07-11 18:07:03.000000000 +0200
@@ -224,6 +224,26 @@ static struct file_operations fragmentat
.release = seq_release,
};
+#ifdef CONFIG_MM_REFAULT
+extern struct seq_operations refault_op;
+static int refault_open(struct inode *inode, struct file *file)
+{
+ (void)inode;
+ return seq_open(file, &refault_op);
+}
+
+extern ssize_t refault_write(struct file *, const char __user *buf,
+ size_t count, loff_t *);
+
+static struct file_operations refault_file_operations = {
+ .open = refault_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+ .write = refault_write,
+};
+#endif
+
extern struct seq_operations zoneinfo_op;
static int zoneinfo_open(struct inode *inode, struct file *file)
{
@@ -696,6 +716,9 @@ void __init proc_misc_init(void)
#endif
#endif
create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
+#ifdef CONFIG_MM_REFAULT
+ create_seq_entry("refault",S_IRUGO, &refault_file_operations);
+#endif
create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);
create_seq_entry("zoneinfo",S_IRUGO, &proc_zoneinfo_file_operations);
create_seq_entry("diskstats", 0, &proc_diskstats_operations);
Index: linux-2.6/mm/Kconfig
===================================================================
--- linux-2.6.orig/mm/Kconfig 2006-07-11 18:07:03.000000000 +0200
+++ linux-2.6/mm/Kconfig 2006-07-11 18:07:03.000000000 +0200
@@ -156,3 +156,8 @@ config RESOURCES_64BIT
config MM_NONRESIDENT
bool "Track nonresident pages"
def_bool y
+
+config MM_REFAULT
+ bool "Refault histogram"
+ def_bool y
+ depends on MM_NONRESIDENT
Index: linux-2.6/mm/nonresident.c
===================================================================
--- linux-2.6.orig/mm/nonresident.c 2006-07-11 18:07:03.000000000 +0200
+++ linux-2.6/mm/nonresident.c 2006-07-11 18:07:03.000000000 +0200
@@ -90,12 +90,21 @@ unsigned long nonresident_get(struct add
nr_bucket->page[i] = 0;
/* Return the distance between entry and clock hand. */
distance = atomic_read(&nr_bucket->hand) + NUM_NR - i;
- distance %= NUM_NR;
- return (distance << nonres_shift) + (nr_bucket - nonres_table);
+ distance = (distance % NUM_NR) << nonres_shift;
+ distance += (nr_bucket - nonres_table);
+ goto out;
}
}
- return ~0UL;
+ distance = ~0UL;
+out:
+#ifdef CONFIG_MM_REFAULT
+ {
+ extern void nonresident_refault(unsigned long);
+ nonresident_refault(distance);
+ }
+#endif /* CONFIG_MM_REFAULT */
+ return distance;
}
u32 nonresident_put(struct address_space * mapping, unsigned long index)
Index: linux-2.6/mm/refault.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/mm/refault.c 2006-07-11 18:07:03.000000000 +0200
@@ -0,0 +1,114 @@
+#include <linux/config.h>
+#include <linux/percpu.h>
+#include <linux/seq_file.h>
+#include <asm/uaccess.h>
+
+#define BUCKETS 64
+
+DEFINE_PER_CPU(unsigned long[BUCKETS+1], refault_histogram);
+
+extern unsigned long nonresident_total(void);
+
+void nonresident_refault(unsigned long distance)
+{
+ unsigned long nonres_bucket = nonresident_total() / BUCKETS;
+ unsigned long bucket_id = distance / nonres_bucket;
+
+ if (bucket_id > BUCKETS)
+ bucket_id = BUCKETS;
+
+ __get_cpu_var(refault_histogram)[bucket_id]++;
+}
+
+#ifdef CONFIG_PROC_FS
+
+#include <linux/seq_file.h>
+
+static void *frag_start(struct seq_file *m, loff_t *pos)
+{
+ if (*pos < 0 || *pos > BUCKETS)
+ return NULL;
+
+ m->private = (void *)(unsigned long)*pos;
+
+ return pos;
+}
+
+static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
+{
+ if (*pos < BUCKETS) {
+ (*pos)++;
+ (unsigned long)m->private++;
+ return pos;
+ }
+ return NULL;
+}
+
+static void frag_stop(struct seq_file *m, void *arg)
+{
+}
+
+unsigned long get_refault_stat(unsigned long index)
+{
+ unsigned long total = 0;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ total += per_cpu(refault_histogram, cpu)[index];
+ }
+ return total;
+}
+
+static int frag_show(struct seq_file *m, void *arg)
+{
+ unsigned long index = (unsigned long)m->private;
+ unsigned long nonres_bucket = nonresident_total() / BUCKETS;
+ unsigned long upper = ((unsigned long)index + 1) * nonres_bucket;
+ unsigned long lower = (unsigned long)index * nonres_bucket;
+ unsigned long hits = get_refault_stat(index);
+
+ if (index == 0)
+ seq_printf(m, " Refault distance Hits\n");
+
+ if (index < BUCKETS)
+ seq_printf(m, "%9lu - %9lu %9lu\n", lower, upper, hits);
+ else
+ seq_printf(m, " New/Beyond %9lu %9lu\n", lower, hits);
+
+ return 0;
+}
+
+struct seq_operations refault_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = frag_show,
+};
+
+static void refault_reset(void)
+{
+ int cpu;
+ int bucket_id;
+
+ for_each_possible_cpu(cpu) {
+ for (bucket_id = 0; bucket_id <= BUCKETS; ++bucket_id)
+ per_cpu(refault_histogram, cpu)[bucket_id] = 0;
+ }
+}
+
+ssize_t refault_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ if (count) {
+ char c;
+
+ if (get_user(c, buf))
+ return -EFAULT;
+ if (c == '0')
+ refault_reset();
+ }
+ return count;
+}
+
+#endif /* CONFIG_PROCFS */
+
Index: linux-2.6/mm/Makefile
===================================================================
--- linux-2.6.orig/mm/Makefile 2006-07-11 18:07:03.000000000 +0200
+++ linux-2.6/mm/Makefile 2006-07-11 18:07:03.000000000 +0200
@@ -14,6 +14,7 @@ obj-y := bootmem.o filemap.o mempool.o
obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
obj-$(CONFIG_MM_NONRESIDENT) += nonresident.o
+obj-$(CONFIG_MM_REFAULT) += refault.o
obj-$(CONFIG_HUGETLBFS) += hugetlb.o
obj-$(CONFIG_NUMA) += mempolicy.o
obj-$(CONFIG_SPARSEMEM) += sparse.o
-
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