On Feb 14, 2012, at 10:44 AM, Andy Adamson wrote:
> I have an early patch set that prints session stats for MDS and for
> DS. The DS pnfs_layoutdriver_type interface for session stats takes
> the same arguments as the RPC iostats interface, a seq_file* and a
> struct nfs4_deviceid_node.
>
>>>>>>> + void (*ds_rpc_print_iostats) (struct seq_file *,
>>>>>>> + struct nfs4_deviceid_node *);
>
> We can use the same interface for RPC and session stats. I suggest
> you rename this to "ds_stats" and add an enum type to identify which
> stats are being requested.
>
> -->Andy
>
Well, this patch is dead. I reposted a better implementation yesterday (based on Trond's suggestions) that doesn't have to iterate through the DSs, but we can work together to make a common interface for more stats. Once we display per-DS rpc_iostats, there is no getting around the need to iterate through the DSs (like your session stats). I plan on looking at this later today.
-dros
> On Tue, Feb 14, 2012 at 4:31 AM, Benny Halevy <bhalevy@xxxxxxxxxx> wrote:
>> On 2012-02-13 19:58, Adamson, Dros wrote:
>>>
>>> On Feb 13, 2012, at 3:05 AM, Benny Halevy wrote:
>>>
>>>> Sorry for the late response.
>>>>
>>>> On 2012-02-08 23:04, Adamson, Dros wrote:
>>>>>
>>>>> On Feb 8, 2012, at 12:26 PM, Chuck Lever wrote:
>>>>>
>>>>>> Hi-
>>>>>>
>>>>>> On Feb 8, 2012, at 12:10 PM, Weston Andros Adamson wrote:
>>>>>>
>>>>>>> The per-op stats displayed in /self/proc/mountstats are collected in the sunrpc
>>>>>>
>>>>>> You mean /proc/self/mountstats here.
>>>>>
>>>>> oops!
>>>>>
>>>>>>
>>>>>>> layer and are collected per rpc_client. This has worked for nfs thus far
>>>>>>> since only one nfs_client was ever associated with a mountpoint, but with
>>>>>>> NFS4.1+PNFS+filelayout an nfs mount can have more than one nfs_client.
>>>>>>>
>>>>>>> This can be seen with a pnfs mount where no data server is the same as the MDS -
>>>>>>> all reads, writes and commits will never make it into the current mountstats
>>>>>>> output.
>>>>>>>
>>>>>>> I took the approach of keeping the stats from the MDS and DSs separate in the
>>>>>>> /proc/self/mountstats output to avoid doing too much in the kernel, and to
>>>>>>> expose the fact that these stats are from separate connections (maybe for later
>>>>>>> use).
>>>>>>>
>>>>>>> This method has issues:
>>>>>>>
>>>>>>> 1) even changing the "statvers" of mountstats doesn't stop the userland
>>>>>>> mountstats(8) from trying to parse this output -- and it does so
>>>>>>> incorrectly.
>>>>>>
>>>>>> User land is broken then. :-)
>>>>>
>>>>> Agreed!
>>>>>
>>>>>>
>>>>>>> 2) when using DS multipath this method fails to count operations that happened
>>>>>>> on a different path to the same DS (after a failure).
>>>>>
>>>>> I should have noted that this isn't a problem yet because I haven't submitted the multipath failover patches :)
>>>>>
>>>>>>>
>>>>>>> 3) currently this will display stats twice when DS == MDS.
>>>>>>
>>>>>> Why is this case hard to detect in the kernel or in mountstats?
>>>>>
>>>>> Not hard, just an issue with the current patch.
>>>>>
>>>>>>
>>>>>>>
>>>>>>> So... What should I do here?
>>>>>>>
>>>>>>> A different approach is to add support in net/sunrpc to specify a "parent"
>>>>>>> stat structure so that operations on DS nfs_clients bump stats on
>>>>>>> the main nfs_server->nfs_client->rpc_client. This would take care of all the
>>>>>>> issues with the current patch, but seems like a hack.
>>>>>>
>>>>>> Is this the same as displaying all data in one set of stats?
>>>>>
>>>>> Yes
>>>>>
>>>>>>
>>>>>> Seems like that might be the best next step, then we can split up the MDS and DS stats at some later point.
>>>>
>>>> Splitting up the MDS/DS stats is important to tell when DS I/O is being
>>>> done and how effective it is.
>>>>
>>>> Benny
>>>>
>>>
>>> Agreed! It just can't go into mountstats right away (due to statsvers= not being interpreted in mountstats(8)). I'll make a second patch on top of my mountstats changes to add per-DS stats in /proc/fs/nfsfs/ and we can figure out if we want to add it to mountstats later.
>>>
>>> Does this sound OK?
>>
>> Absolutely. Thanks!
>>
>> Benny
>>
>>>
>>> -dros
>>>
>>>>>
>>>>> Ok, I'll try to do that.
>>>>>
>>>>> Any advice on how to handle the "xprt: …" line? Obviously the different underlying rpc_clients will have different values. I'd have to look at mountstats(8) some more, but I *think* we could just make it a comma separated list.
>>>>>
>>>>> For the 'next step', we can use this patch - we just need to figure out where it should go. Do we keep it in /proc/self/mountstats? I think because of problem #2 we might want to move them out to somewhere in /proc/fs/nfsfs/ along with other per-DS statistics.
>>>>>
>>>>>>
>>>>>>> One task that seems like a good thing to do is to fix mountstats(8) to respect
>>>>>>> the "statsvers" value.
>>>>>>
>>>>>> Agree.
>>>>>
>>>>> I'll do this first.
>>>>>
>>>>> Thanks Chuck!
>>>>>
>>>>> -dros
>>>>>
>>>>>>
>>>>>>>
>>>>>>> Thoughts?
>>>>>>> ---
>>>>>>>
>>>>>>> I cleaned up this patch, but I still have reservations (noted in commit message)
>>>>>>>
>>>>>>> fs/nfs/nfs4filelayout.c | 23 +++++++++++++++++++++++
>>>>>>> fs/nfs/pnfs.h | 20 ++++++++++++++++++++
>>>>>>> fs/nfs/pnfs_dev.c | 25 +++++++++++++++++++++++++
>>>>>>> fs/nfs/super.c | 1 +
>>>>>>> include/linux/nfs_iostat.h | 2 +-
>>>>>>> 5 files changed, 70 insertions(+), 1 deletions(-)
>>>>>>>
>>>>>>> diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
>>>>>>> index 79be7ac..9410fd0 100644
>>>>>>> --- a/fs/nfs/nfs4filelayout.c
>>>>>>> +++ b/fs/nfs/nfs4filelayout.c
>>>>>>> @@ -33,6 +33,8 @@
>>>>>>> #include <linux/nfs_page.h>
>>>>>>> #include <linux/module.h>
>>>>>>>
>>>>>>> +#include <linux/sunrpc/metrics.h>
>>>>>>> +
>>>>>>> #include "internal.h"
>>>>>>> #include "nfs4filelayout.h"
>>>>>>>
>>>>>>> @@ -918,6 +920,26 @@ filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
>>>>>>> nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
>>>>>>> }
>>>>>>>
>>>>>>> +static void
>>>>>>> +filelayout_rpc_print_iostats(struct seq_file *m, struct nfs4_deviceid_node *d)
>>>>>>> +{
>>>>>>> + struct nfs4_file_layout_dsaddr *dsaddr;
>>>>>>> + struct nfs4_pnfs_ds *ds;
>>>>>>> + u32 i;
>>>>>>> +
>>>>>>> + dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
>>>>>>> +
>>>>>>> + for (i = 0; i < dsaddr->ds_num; i++) {
>>>>>>> + ds = dsaddr->ds_list[i];
>>>>>>> +
>>>>>>> + if (ds && ds->ds_clp) {
>>>>>>> + seq_printf(m, " pnfs dataserver %s\n",
>>>>>>> + ds->ds_remotestr);
>>>>>>> + rpc_print_iostats(m, ds->ds_clp->cl_rpcclient);
>>>>>>> + }
>>>>>>> + }
>>>>>>> +}
>>>>>>> +
>>>>>>> static struct pnfs_layoutdriver_type filelayout_type = {
>>>>>>> .id = LAYOUT_NFSV4_1_FILES,
>>>>>>> .name = "LAYOUT_NFSV4_1_FILES",
>>>>>>> @@ -932,6 +954,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
>>>>>>> .read_pagelist = filelayout_read_pagelist,
>>>>>>> .write_pagelist = filelayout_write_pagelist,
>>>>>>> .free_deviceid_node = filelayout_free_deveiceid_node,
>>>>>>> + .ds_rpc_print_iostats = filelayout_rpc_print_iostats,
>>>>>>> };
>>>>>>>
>>>>>>> static int __init nfs4filelayout_init(void)
>>>>>>> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
>>>>>>> index 53d593a..0a5e020 100644
>>>>>>> --- a/fs/nfs/pnfs.h
>>>>>>> +++ b/fs/nfs/pnfs.h
>>>>>>> @@ -119,6 +119,9 @@ struct pnfs_layoutdriver_type {
>>>>>>> void (*encode_layoutcommit) (struct pnfs_layout_hdr *layoutid,
>>>>>>> struct xdr_stream *xdr,
>>>>>>> const struct nfs4_layoutcommit_args *args);
>>>>>>> +
>>>>>>> + void (*ds_rpc_print_iostats) (struct seq_file *,
>>>>>>> + struct nfs4_deviceid_node *);
>>>>>>> };
>>>>>>>
>>>>>>> struct pnfs_layout_hdr {
>>>>>>> @@ -239,6 +242,10 @@ void nfs4_init_deviceid_node(struct nfs4_deviceid_node *,
>>>>>>> struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
>>>>>>> bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
>>>>>>> void nfs4_deviceid_purge_client(const struct nfs_client *);
>>>>>>> +void nfs4_deviceid_rpc_print_iostats(struct seq_file *seq,
>>>>>>> + const struct nfs_client *clp,
>>>>>>> + const struct pnfs_layoutdriver_type *ld);
>>>>>>> +
>>>>>>>
>>>>>>> static inline int lo_fail_bit(u32 iomode)
>>>>>>> {
>>>>>>> @@ -328,6 +335,14 @@ static inline int pnfs_return_layout(struct inode *ino)
>>>>>>> return 0;
>>>>>>> }
>>>>>>>
>>>>>>> +static inline void
>>>>>>> +pnfs_rpc_print_iostats(struct seq_file *m, struct nfs_server *nfss)
>>>>>>> +{
>>>>>>> + if (!pnfs_enabled_sb(nfss))
>>>>>>> + return;
>>>>>>> + nfs4_deviceid_rpc_print_iostats(m, nfss->nfs_client,
>>>>>>> + nfss->pnfs_curr_ld);
>>>>>>> +}
>>>>>>> #else /* CONFIG_NFS_V4_1 */
>>>>>>>
>>>>>>> static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
>>>>>>> @@ -429,6 +444,11 @@ static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
>>>>>>> static inline void nfs4_deviceid_purge_client(struct nfs_client *ncl)
>>>>>>> {
>>>>>>> }
>>>>>>> +
>>>>>>> +static inline void
>>>>>>> +pnfs_rpc_print_iostats(struct seq_file *m, struct nfs_server *nfss)
>>>>>>> +{
>>>>>>> +}
>>>>>>> #endif /* CONFIG_NFS_V4_1 */
>>>>>>>
>>>>>>> #endif /* FS_NFS_PNFS_H */
>>>>>>> diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
>>>>>>> index 4f359d2..277de87 100644
>>>>>>> --- a/fs/nfs/pnfs_dev.c
>>>>>>> +++ b/fs/nfs/pnfs_dev.c
>>>>>>> @@ -115,6 +115,31 @@ nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
>>>>>>> }
>>>>>>> EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
>>>>>>>
>>>>>>> +
>>>>>>> +void
>>>>>>> +nfs4_deviceid_rpc_print_iostats(struct seq_file *seq,
>>>>>>> + const struct nfs_client *clp,
>>>>>>> + const struct pnfs_layoutdriver_type *ld)
>>>>>>> +{
>>>>>>> + struct nfs4_deviceid_node *d;
>>>>>>> + struct hlist_node *n;
>>>>>>> + long h;
>>>>>>> +
>>>>>>> + if (!ld->ds_rpc_print_iostats)
>>>>>>> + return;
>>>>>>> +
>>>>>>> + rcu_read_lock();
>>>>>>> + for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++) {
>>>>>>> + hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[h], node)
>>>>>>> + if (d->ld == ld && d->nfs_client == clp) {
>>>>>>> + if (atomic_read(&d->ref))
>>>>>>> + ld->ds_rpc_print_iostats(seq, d);
>>>>>>> + }
>>>>>>> + }
>>>>>>> + rcu_read_unlock();
>>>>>>> +}
>>>>>>> +EXPORT_SYMBOL_GPL(nfs4_deviceid_rpc_print_iostats);
>>>>>>> +
>>>>>>> /*
>>>>>>> * Remove a deviceid from cache
>>>>>>> *
>>>>>>> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>>>>>>> index d18a90b..453e496 100644
>>>>>>> --- a/fs/nfs/super.c
>>>>>>> +++ b/fs/nfs/super.c
>>>>>>> @@ -871,6 +871,7 @@ static int nfs_show_stats(struct seq_file *m, struct dentry *root)
>>>>>>> seq_printf(m, "\n");
>>>>>>>
>>>>>>> rpc_print_iostats(m, nfss->client);
>>>>>>> + pnfs_rpc_print_iostats(m, nfss);
>>>>>>>
>>>>>>> return 0;
>>>>>>> }
>>>>>>> diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
>>>>>>> index 8866bb3..7fe4605 100644
>>>>>>> --- a/include/linux/nfs_iostat.h
>>>>>>> +++ b/include/linux/nfs_iostat.h
>>>>>>> @@ -21,7 +21,7 @@
>>>>>>> #ifndef _LINUX_NFS_IOSTAT
>>>>>>> #define _LINUX_NFS_IOSTAT
>>>>>>>
>>>>>>> -#define NFS_IOSTAT_VERS "1.0"
>>>>>>> +#define NFS_IOSTAT_VERS "2.0"
>>>>>>>
>>>>>>> /*
>>>>>>> * NFS byte counters
>>>>>>> --
>>>>>>> 1.7.4.4
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> Chuck Lever
>>>>>> chuck[dot]lever[at]oracle[dot]com
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>> --
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>>>
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