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author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-06-24 08:41:41 -0400 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-06-24 13:07:53 -0400 |
commit | 816724e65c72a90a44fbad0ef0b59b186c85fa90 (patch) | |
tree | 421fa29aedff988e392f92780637553e275d37a0 /lib/percpu_counter.c | |
parent | 70ac4385a13f78bc478f26d317511893741b05bd (diff) | |
parent | d384ea691fe4ea8c2dd5b9b8d9042eb181776f18 (diff) |
Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
Conflicts:
fs/nfs/inode.c
fs/super.c
Fix conflicts between patch 'NFS: Split fs/nfs/inode.c' and patch
'VFS: Permit filesystem to override root dentry on mount'
Diffstat (limited to 'lib/percpu_counter.c')
-rw-r--r-- | lib/percpu_counter.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c new file mode 100644 index 00000000000..850449080e1 --- /dev/null +++ b/lib/percpu_counter.c @@ -0,0 +1,46 @@ +/* + * Fast batching percpu counters. + */ + +#include <linux/percpu_counter.h> +#include <linux/module.h> + +void percpu_counter_mod(struct percpu_counter *fbc, s32 amount) +{ + long count; + s32 *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_counter_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() + */ +s64 percpu_counter_sum(struct percpu_counter *fbc) +{ + s64 ret; + int cpu; + + spin_lock(&fbc->lock); + ret = fbc->count; + for_each_possible_cpu(cpu) { + s32 *pcount = per_cpu_ptr(fbc->counters, cpu); + ret += *pcount; + } + spin_unlock(&fbc->lock); + return ret < 0 ? 0 : ret; +} +EXPORT_SYMBOL(percpu_counter_sum); |