[RFC][1/21]ext3 add new percpu_counter
From: sho
Date: Thu Apr 13 2006 - 03:02:55 EST
Summary of this patch:
[1/21] add percpu_llcounter for ext3
- The number of blocks and inodes are counted using
percpu_counter whose entry for counter is long type, so it
can only have less than 2G-1. Then I add percpu_llcounter
whose entry for counter is long long type in ext3.
Signed-off-by: Takashi Sato sho@xxxxxxxxxxxxxx
---
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/fs/ext3/balloc.c linux-2.6.17-rc1.tmp/fs/ext3/balloc.c
--- linux-2.6.17-rc1/fs/ext3/balloc.c 2006-04-10 09:40:49.000000000 +0900
+++ linux-2.6.17-rc1.tmp/fs/ext3/balloc.c 2006-04-10 09:41:02.000000000 +0900
@@ -467,7 +467,7 @@ do_more:
cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) +
group_freed);
spin_unlock(sb_bgl_lock(sbi, block_group));
- percpu_counter_mod(&sbi->s_freeblocks_counter, count);
+ percpu_llcounter_mod(&sbi->s_freeblocks_counter, count);
/* We dirtied the bitmap block */
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
@@ -1168,7 +1168,7 @@ static int ext3_has_free_blocks(struct e
{
unsigned long free_blocks, root_blocks;
- free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+ free_blocks = percpu_llcounter_read_positive(&sbi->s_freeblocks_counter);
root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
sbi->s_resuid != current->fsuid &&
@@ -1431,7 +1431,7 @@ allocated:
gdp->bg_free_blocks_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - num);
spin_unlock(sb_bgl_lock(sbi, group_no));
- percpu_counter_mod(&sbi->s_freeblocks_counter, -num);
+ percpu_llcounter_mod(&sbi->s_freeblocks_counter, -(long long)num);
BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor");
err = ext3_journal_dirty_metadata(handle, gdp_bh);
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/fs/ext3/ialloc.c linux-2.6.17-rc1.tmp/fs/ext3/ialloc.c
--- linux-2.6.17-rc1/fs/ext3/ialloc.c 2006-04-10 09:40:49.000000000 +0900
+++ linux-2.6.17-rc1.tmp/fs/ext3/ialloc.c 2006-04-10 09:41:02.000000000 +0900
@@ -170,9 +170,9 @@ void ext3_free_inode (handle_t *handle,
gdp->bg_used_dirs_count = cpu_to_le16(
le16_to_cpu(gdp->bg_used_dirs_count) - 1);
spin_unlock(sb_bgl_lock(sbi, block_group));
- percpu_counter_inc(&sbi->s_freeinodes_counter);
+ percpu_llcounter_inc(&sbi->s_freeinodes_counter);
if (is_directory)
- percpu_counter_dec(&sbi->s_dirs_counter);
+ percpu_llcounter_dec(&sbi->s_dirs_counter);
}
BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
@@ -207,7 +207,7 @@ static int find_group_dir(struct super_b
struct buffer_head *bh;
int group, best_group = -1;
- freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
+ freei = percpu_llcounter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
avefreei = freei / ngroups;
for (group = 0; group < ngroups; group++) {
@@ -269,11 +269,11 @@ static int find_group_orlov(struct super
struct ext3_group_desc *desc;
struct buffer_head *bh;
- freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
+ freei = percpu_llcounter_read_positive(&sbi->s_freeinodes_counter);
avefreei = freei / ngroups;
- freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+ freeb = percpu_llcounter_read_positive(&sbi->s_freeblocks_counter);
avefreeb = freeb / ngroups;
- ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
+ ndirs = percpu_llcounter_read_positive(&sbi->s_dirs_counter);
if ((parent == sb->s_root->d_inode) ||
(EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
@@ -539,9 +539,9 @@ got:
err = ext3_journal_dirty_metadata(handle, bh2);
if (err) goto fail;
- percpu_counter_dec(&sbi->s_freeinodes_counter);
+ percpu_llcounter_dec(&sbi->s_freeinodes_counter);
if (S_ISDIR(mode))
- percpu_counter_inc(&sbi->s_dirs_counter);
+ percpu_llcounter_inc(&sbi->s_dirs_counter);
sb->s_dirt = 1;
inode->i_uid = current->fsuid;
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/fs/ext3/resize.c linux-2.6.17-rc1.tmp/fs/ext3/resize.c
--- linux-2.6.17-rc1/fs/ext3/resize.c 2006-04-10 09:40:49.000000000 +0900
+++ linux-2.6.17-rc1.tmp/fs/ext3/resize.c 2006-04-10 09:41:02.000000000 +0900
@@ -869,9 +869,9 @@ int ext3_group_add(struct super_block *s
input->reserved_blocks);
/* Update the free space counts */
- percpu_counter_mod(&sbi->s_freeblocks_counter,
+ percpu_llcounter_mod(&sbi->s_freeblocks_counter,
input->free_blocks_count);
- percpu_counter_mod(&sbi->s_freeinodes_counter,
+ percpu_llcounter_mod(&sbi->s_freeinodes_counter,
EXT3_INODES_PER_GROUP(sb));
ext3_journal_dirty_metadata(handle, sbi->s_sbh);
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/fs/ext3/super.c linux-2.6.17-rc1.tmp/fs/ext3/super.c
--- linux-2.6.17-rc1/fs/ext3/super.c 2006-04-03 12:22:10.000000000 +0900
+++ linux-2.6.17-rc1.tmp/fs/ext3/super.c 2006-04-10 09:41:02.000000000 +0900
@@ -403,9 +403,9 @@ static void ext3_put_super (struct super
for (i = 0; i < sbi->s_gdb_count; i++)
brelse(sbi->s_group_desc[i]);
kfree(sbi->s_group_desc);
- percpu_counter_destroy(&sbi->s_freeblocks_counter);
- percpu_counter_destroy(&sbi->s_freeinodes_counter);
- percpu_counter_destroy(&sbi->s_dirs_counter);
+ percpu_llcounter_destroy(&sbi->s_freeblocks_counter);
+ percpu_llcounter_destroy(&sbi->s_freeinodes_counter);
+ percpu_llcounter_destroy(&sbi->s_dirs_counter);
brelse(sbi->s_sbh);
#ifdef CONFIG_QUOTA
for (i = 0; i < MAXQUOTAS; i++)
@@ -1579,9 +1579,9 @@ static int ext3_fill_super (struct super
goto failed_mount;
}
- percpu_counter_init(&sbi->s_freeblocks_counter);
- percpu_counter_init(&sbi->s_freeinodes_counter);
- percpu_counter_init(&sbi->s_dirs_counter);
+ percpu_llcounter_init(&sbi->s_freeblocks_counter);
+ percpu_llcounter_init(&sbi->s_freeinodes_counter);
+ percpu_llcounter_init(&sbi->s_dirs_counter);
bgl_lock_init(&sbi->s_blockgroup_lock);
for (i = 0; i < db_count; i++) {
@@ -1723,11 +1723,11 @@ static int ext3_fill_super (struct super
test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
"writeback");
- percpu_counter_mod(&sbi->s_freeblocks_counter,
+ percpu_llcounter_mod(&sbi->s_freeblocks_counter,
ext3_count_free_blocks(sb));
- percpu_counter_mod(&sbi->s_freeinodes_counter,
+ percpu_llcounter_mod(&sbi->s_freeinodes_counter,
ext3_count_free_inodes(sb));
- percpu_counter_mod(&sbi->s_dirs_counter,
+ percpu_llcounter_mod(&sbi->s_dirs_counter,
ext3_count_dirs(sb));
lock_kernel();
@@ -2363,12 +2363,12 @@ static int ext3_statfs (struct super_blo
buf->f_type = EXT3_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;
- buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
+ buf->f_bfree = percpu_llcounter_sum(&sbi->s_freeblocks_counter);
buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
buf->f_bavail = 0;
buf->f_files = le32_to_cpu(es->s_inodes_count);
- buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
+ buf->f_ffree = percpu_llcounter_sum(&sbi->s_freeinodes_counter);
buf->f_namelen = EXT3_NAME_LEN;
return 0;
}
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/include/linux/ext3_fs_sb.h linux-2.6.17-rc1.tmp/include/linux/ext3_fs_sb.h
--- linux-2.6.17-rc1/include/linux/ext3_fs_sb.h 2006-04-03 12:22:10.000000000 +0900
+++ linux-2.6.17-rc1.tmp/include/linux/ext3_fs_sb.h 2006-04-10 09:41:02.000000000 +0900
@@ -20,7 +20,7 @@
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/blockgroup_lock.h>
-#include <linux/percpu_counter.h>
+#include <linux/percpu_llcounter.h>
#endif
#include <linux/rbtree.h>
@@ -54,9 +54,9 @@ struct ext3_sb_info {
u32 s_next_generation;
u32 s_hash_seed[4];
int s_def_hash_version;
- struct percpu_counter s_freeblocks_counter;
- struct percpu_counter s_freeinodes_counter;
- struct percpu_counter s_dirs_counter;
+ struct percpu_llcounter s_freeblocks_counter;
+ struct percpu_llcounter s_freeinodes_counter;
+ struct percpu_llcounter s_dirs_counter;
struct blockgroup_lock s_blockgroup_lock;
/* root of the per fs reservation window tree */
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/include/linux/percpu_llcounter.h linux-2.6.17-rc1.tmp/include/linux/percpu_llcounter.h
--- linux-2.6.17-rc1/include/linux/percpu_llcounter.h 1970-01-01 09:00:00.000000000 +0900
+++ linux-2.6.17-rc1.tmp/include/linux/percpu_llcounter.h 2006-04-10 09:41:02.000000000 +0900
@@ -0,0 +1,113 @@
+#ifndef _LINUX_LLPERCPU_COUNTER_H
+#define _LINUX_LLPERCPU_COUNTER_H
+/*
+ * A simple "approximate counter" for use in ext2 and ext3 superblocks.
+ *
+ * WARNING: these things are HUGE. 4 kbytes per counter on 32-way P4.
+ */
+
+#include <linux/config.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+#include <linux/percpu.h>
+
+#ifdef CONFIG_SMP
+
+struct percpu_llcounter {
+ spinlock_t lock;
+ long long count;
+ long long *counters;
+};
+
+#if NR_CPUS >= 16
+#define FBC_BATCH (NR_CPUS*2)
+#else
+#define FBC_BATCH (NR_CPUS*4)
+#endif
+
+static inline void percpu_llcounter_init(struct percpu_llcounter *fbc)
+{
+ spin_lock_init(&fbc->lock);
+ fbc->count = 0;
+ fbc->counters = alloc_percpu(long long);
+}
+
+static inline void percpu_llcounter_destroy(struct percpu_llcounter *fbc)
+{
+ free_percpu(fbc->counters);
+}
+
+void percpu_llcounter_mod(struct percpu_llcounter *fbc, long long amount);
+long long percpu_llcounter_sum(struct percpu_llcounter *fbc);
+
+static inline long long percpu_llcounter_read(struct percpu_llcounter *fbc)
+{
+ return fbc->count;
+}
+
+/*
+ * It is possible for the percpu_llcounter_read() to return a small negative
+ * number for some counter which should never be negative.
+ */
+static inline long long percpu_llcounter_read_positive(struct percpu_llcounter *fbc)
+{
+ long long ret = fbc->count;
+
+ barrier(); /* Prevent reloads of fbc->count */
+ if (ret > 0)
+ return ret;
+ return 1;
+}
+
+#else
+
+struct percpu_llcounter {
+ long long count;
+};
+
+static inline void percpu_llcounter_init(struct percpu_llcounter *fbc)
+{
+ fbc->count = 0;
+}
+
+static inline void percpu_llcounter_destroy(struct percpu_llcounter *fbc)
+{
+}
+
+static inline void
+percpu_llcounter_mod(struct percpu_llcounter *fbc, long long amount)
+{
+ preempt_disable();
+ fbc->count += amount;
+ preempt_enable();
+}
+
+static inline long long percpu_llcounter_read(struct percpu_llcounter *fbc)
+{
+ return fbc->count;
+}
+
+static inline long long percpu_llcounter_read_positive(struct percpu_llcounter *fbc)
+{
+ return fbc->count;
+}
+
+static inline long long percpu_llcounter_sum(struct percpu_llcounter *fbc)
+{
+ return percpu_llcounter_read_positive(fbc);
+}
+
+#endif /* CONFIG_SMP */
+
+static inline void percpu_llcounter_inc(struct percpu_llcounter *fbc)
+{
+ percpu_llcounter_mod(fbc, 1);
+}
+
+static inline void percpu_llcounter_dec(struct percpu_llcounter *fbc)
+{
+ percpu_llcounter_mod(fbc, -1);
+}
+
+#endif /* _LINUX_LLPERCPU_COUNTER_H */
diff -upNr -X linux-2.6.17-rc1/Documentation/dontdiff linux-2.6.17-rc1/mm/swap.c linux-2.6.17-rc1.tmp/mm/swap.c
--- linux-2.6.17-rc1/mm/swap.c 2006-04-03 12:22:10.000000000 +0900
+++ linux-2.6.17-rc1.tmp/mm/swap.c 2006-04-10 09:41:45.000000000 +0900
@@ -26,6 +26,7 @@
#include <linux/buffer_head.h> /* for try_to_release_page() */
#include <linux/module.h>
#include <linux/percpu_counter.h>
+#include <linux/percpu_llcounter.h>
#include <linux/percpu.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
@@ -501,6 +502,26 @@ void percpu_counter_mod(struct percpu_co
}
EXPORT_SYMBOL(percpu_counter_mod);
+void percpu_llcounter_mod(struct percpu_llcounter *fbc, long long amount)
+{
+ long long count;
+ long long *pcount;
+ int cpu = get_cpu();
+
+ pcount = per_cpu_ptr(fbc->counters, cpu);
+ count = *pcount + amount;
+ if (count >= FBC_BATCH || count <= -FBC_BATCH) {
+ spin_lock(&fbc->lock);
+ fbc->count += count;
+ *pcount = 0;
+ spin_unlock(&fbc->lock);
+ } else {
+ *pcount = count;
+ }
+ put_cpu();
+}
+EXPORT_SYMBOL(percpu_llcounter_mod);
+
/*
* Add up all the per-cpu counts, return the result. This is a more accurate
* but much slower version of percpu_counter_read_positive()
@@ -520,6 +541,26 @@ long percpu_counter_sum(struct percpu_co
return ret < 0 ? 0 : ret;
}
EXPORT_SYMBOL(percpu_counter_sum);
+
+/*
+ * Add up all the per-cpu counts, return the result. This is a more accurate
+ * but much slower version of percpu_llcounter_read_positive()
+ */
+long long percpu_llcounter_sum(struct percpu_llcounter *fbc)
+{
+ long long ret;
+ int cpu;
+
+ spin_lock(&fbc->lock);
+ ret = fbc->count;
+ for_each_cpu(cpu) {
+ long long *pcount = per_cpu_ptr(fbc->counters, cpu);
+ ret += *pcount;
+ }
+ spin_unlock(&fbc->lock);
+ return ret < 0 ? 0 : ret;
+}
+EXPORT_SYMBOL(percpu_llcounter_sum);
#endif
/*
-
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