On Tue, Apr 28, 2009 at 11:37:09AM -0400, Chuck Lever wrote: > > On Apr 27, 2009, at 7:22 PM, J. Bruce Fields wrote: > >> On Mon, Apr 27, 2009 at 12:06:18PM -0400, Chuck Lever wrote: >>> On Apr 25, 2009, at 6:03 PM, J. Bruce Fields wrote: >>>> Pfft, did it again. >>>> >>>> --b. >>>> >>>> On Sat, Apr 25, 2009 at 05:57:45PM -0400, bfields wrote: >>>>> On Wed, Apr 01, 2009 at 07:28:03AM +1100, Greg Banks wrote: >>>>>> Add two control files to /proc/fs/nfsd: >>>>>> >>>>>> * "stats_enabled" can be used to disable or enable the gathering >>>>>> of per-client and per-export statistics in the server. >>>>>> >>>>>> * "stats_prune_period" can be used to set the period at >>>>>> which the pruning timer runs, in seconds. Unused stats >>>>>> entries will survive at most twice that time. >>>>>> >>>>>> Signed-off-by: Greg Banks <gnb@xxxxxxx> >>>>>> --- >>>>>> >>>>>> fs/nfsd/nfsctl.c | 99 >>>>>> ++++++++++++++++++++++++++++++++++++++++++++ >>>>>> 1 file changed, 99 insertions(+) >>>>>> >>>>>> Index: bfields/fs/nfsd/nfsctl.c >>>>>> = >>>>>> ================================================================== >>>>>> --- bfields.orig/fs/nfsd/nfsctl.c >>>>>> +++ bfields/fs/nfsd/nfsctl.c >>>>>> @@ -64,6 +64,8 @@ enum { >>>>>> NFSD_Versions, >>>>>> NFSD_Ports, >>>>>> NFSD_MaxBlkSize, >>>>>> + NFSD_Stats_Enabled, >>>>>> + NFSD_Stats_Prune_Period, >>>>>> /* >>>>>> * The below MUST come last. Otherwise we leave a hole in >>>>>> nfsd_files[] >>>>>> * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops >>>>>> @@ -92,6 +94,8 @@ static ssize_t write_pool_threads(struct >>>>>> static ssize_t write_versions(struct file *file, char *buf, size_t >>>>>> size); >>>>>> static ssize_t write_ports(struct file *file, char *buf, size_t >>>>>> size); >>>>>> static ssize_t write_maxblksize(struct file *file, char *buf, >>>>>> size_t size); >>>>>> +static ssize_t write_stats_enabled(struct file *file, char *buf, >>>>>> size_t size); >>>>>> +static ssize_t write_stats_prune_period(struct file *file, char >>>>>> *buf, size_t size); >>>>>> #ifdef CONFIG_NFSD_V4 >>>>>> static ssize_t write_leasetime(struct file *file, char *buf, >>>>>> size_t size); >>>>>> static ssize_t write_recoverydir(struct file *file, char *buf, >>>>>> size_t size); >>>>>> @@ -113,6 +117,8 @@ static ssize_t (*write_op[])(struct file >>>>>> [NFSD_Versions] = write_versions, >>>>>> [NFSD_Ports] = write_ports, >>>>>> [NFSD_MaxBlkSize] = write_maxblksize, >>>>>> + [NFSD_Stats_Enabled] = write_stats_enabled, >>>>>> + [NFSD_Stats_Prune_Period] = write_stats_prune_period, >>>>>> #ifdef CONFIG_NFSD_V4 >>>>>> [NFSD_Leasetime] = write_leasetime, >>>>>> [NFSD_RecoveryDir] = write_recoverydir, >>>>>> @@ -1121,6 +1127,97 @@ static ssize_t write_maxblksize(struct f >>>>>> return sprintf(buf, "%d\n", nfsd_max_blksize); >>>>>> } >>>>>> >>>>>> +extern int nfsd_stats_enabled; >>>>>> + >>>>>> +/** >>>>>> + * write_stats_enabled - Set or report whether per-client/ >>>>>> + * per-export stats are enabled. >>>>>> + * >>>>>> + * Input: >>>>>> + * buf: ignored >>>>>> + * size: zero >>>>>> + * >>>>>> + * OR >>>>>> + * >>>>>> + * Input: >>>>>> + * buf: C string containing an unsigned >>>>>> + * integer value representing the new value >>>>>> + * size: non-zero length of C string in @buf >>>>>> + * Output: >>>>>> + * On success: passed-in buffer filled with '\n'-terminated C >>>>>> string >>>>>> + * containing numeric value of the current setting >>>>>> + * return code is the size in bytes of the string >>>>>> + * On error: return code is zero or a negative errno value >>>>>> + */ >>>>>> +static ssize_t write_stats_enabled(struct file *file, char *buf, >>>>>> size_t size) >>>>>> +{ >>>>>> + char *mesg = buf; >>>>>> + if (size > 0) { >>>>>> + int enabled; >>>>>> + int rv = get_int(&mesg, &enabled); >>>>>> + if (rv) >>>>>> + return rv; >>>>>> + /* check `enabled' against allowed range */ >>>>>> + if (enabled < 0 || enabled > 1) >>>>>> + return -EINVAL; >>>>>> + /* >>>>>> + * We can change the enabled flag at any time without >>>>>> + * locking. All it controls is whether stats are >>>>>> + * gathered for new incoming NFS calls. Old gathered >>>>>> + * stats still sit around in the hash tables until >>>>>> + * naturally pruned. >>>>>> + */ >>>>>> + nfsd_stats_enabled = enabled; >>>>>> + } >>>>>> + return sprintf(buf, "%d\n", nfsd_stats_enabled); >>>>>> +} >>>>>> + >>>>>> +extern int nfsd_stats_prune_period; >>>>>> + >>>>>> +/** >>>>>> + * write_stats_prune_period - Set or report the period for >>>>>> pruning >>>>>> + * old per-client/per-export stats entries, >>>>>> + * in seconds. >>>>>> + * >>>>>> + * Input: >>>>>> + * buf: ignored >>>>>> + * size: zero >>>>>> + * >>>>>> + * OR >>>>>> + * >>>>>> + * Input: >>>>>> + * buf: C string containing an unsigned >>>>>> + * integer value representing the new value >>>>>> + * size: non-zero length of C string in @buf >>>>>> + * Output: >>>>>> + * On success: passed-in buffer filled with '\n'-terminated C >>>>>> string >>>>>> + * containing numeric value of the current setting >>>>>> + * return code is the size in bytes of the string >>>>>> + * On error: return code is zero or a negative errno value >>>>>> + */ >>>>> >>>>> Just an idle remark, don't worry about this for now, but: we might >>>>> want >>>>> to rein in this write_*() comment format a little some day. A >>>>> lot of >>>>> the content seems duplicated. >>> >>> I disagree. >> >> How? The below seems to be an arguing against *removing* the >> comments, >> or removing information from them, neither of which I'd be in favor >> of. > > Then I misunderstood what you meant by "rein in". > > The apparent content duplication is because these functions are all > slightly different. What we had before was a single description of the > return values at the top of the files that more or less fit each proc > file, but didn't precisely fit any but the oldest. > > (Responding a bit to Greg) IMO highlighting the differences instead > means a person trying to understand this interface has to read the whole > damn nfsctl.c file instead of looking at the one piece s/he is > interested in. This is documentation, not code, so I think a little > text duplication is OK or even actually preferred. Agreed, and I agree that nobody should have to read the whole file. But appropriate cross-references ("foo() behaves like bar() except...") could prevent that. As long as we don't require following too many such references, I think the burden of tracking following references would be outweighed by the benefits of more concise descriptions. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html