[PATCH 36/43] NFS: Add some new I/O counters for FS-Cache doingthings for NFS [ver #46]

From: David Howells
Date: Wed Apr 01 2009 - 19:24:28 EST


Add some new NFS I/O counters for FS-Cache doing things for NFS. A new line is
emitted into /proc/pid/mountstats if caching is enabled that looks like:

fsc: <rok> <rfl> <wok> <wfl> <unc>

Where <rok> is the number of pages read successfully from the cache, <rfl> is
the number of failed page reads against the cache, <wok> is the number of
successful page writes to the cache, <wfl> is the number of failed page writes
to the cache, and <unc> is the number of NFS pages that have been disconnected
from the cache.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Acked-by: Steve Dickson <steved@xxxxxxxxxx>
Acked-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---

fs/nfs/iostat.h | 18 ++++++++++++++++++
fs/nfs/super.c | 11 +++++++++++
include/linux/nfs_iostat.h | 12 ++++++++++++
3 files changed, 41 insertions(+), 0 deletions(-)


diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
index a369528..a2ab252 100644
--- a/fs/nfs/iostat.h
+++ b/fs/nfs/iostat.h
@@ -16,6 +16,9 @@

struct nfs_iostats {
unsigned long long bytes[__NFSIOS_BYTESMAX];
+#ifdef CONFIG_NFS_FSCACHE
+ unsigned long long fscache[__NFSIOS_FSCACHEMAX];
+#endif
unsigned long events[__NFSIOS_COUNTSMAX];
} ____cacheline_aligned;

@@ -57,6 +60,21 @@ static inline void nfs_add_stats(const struct inode *inode,
nfs_add_server_stats(NFS_SERVER(inode), stat, addend);
}

+#ifdef CONFIG_NFS_FSCACHE
+static inline void nfs_add_fscache_stats(struct inode *inode,
+ enum nfs_stat_fscachecounters stat,
+ unsigned long addend)
+{
+ struct nfs_iostats *iostats;
+ int cpu;
+
+ cpu = get_cpu();
+ iostats = per_cpu_ptr(NFS_SERVER(inode)->io_stats, cpu);
+ iostats->fscache[stat] += addend;
+ put_cpu_no_resched();
+}
+#endif
+
static inline struct nfs_iostats *nfs_alloc_iostats(void)
{
return alloc_percpu(struct nfs_iostats);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 87f65ae..b5fea77 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -642,6 +642,10 @@ static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
totals.events[i] += stats->events[i];
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
totals.bytes[i] += stats->bytes[i];
+#ifdef CONFIG_NFS_FSCACHE
+ for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
+ totals.fscache[i] += stats->fscache[i];
+#endif

preempt_enable();
}
@@ -652,6 +656,13 @@ static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
seq_printf(m, "\n\tbytes:\t");
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
seq_printf(m, "%Lu ", totals.bytes[i]);
+#ifdef CONFIG_NFS_FSCACHE
+ if (nfss->options & NFS_OPTION_FSCACHE) {
+ seq_printf(m, "\n\tfsc:\t");
+ for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
+ seq_printf(m, "%Lu ", totals.bytes[i]);
+ }
+#endif
seq_printf(m, "\n");

rpc_print_iostats(m, nfss->client);
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 1cb9a3f..68b10f5 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -116,4 +116,16 @@ enum nfs_stat_eventcounters {
__NFSIOS_COUNTSMAX,
};

+/*
+ * NFS local caching servicing counters
+ */
+enum nfs_stat_fscachecounters {
+ NFSIOS_FSCACHE_PAGES_READ_OK,
+ NFSIOS_FSCACHE_PAGES_READ_FAIL,
+ NFSIOS_FSCACHE_PAGES_WRITTEN_OK,
+ NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL,
+ NFSIOS_FSCACHE_PAGES_UNCACHED,
+ __NFSIOS_FSCACHEMAX,
+};
+
#endif /* _LINUX_NFS_IOSTAT */

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