src/lib/libdevstat/devstat.h, branch release/10.1.0

New devstat metrics for devstat_compute_statistics():

2012-12-15T18:19:48Z

DSM_TOTAL_DURATION DSM_TOTAL_DURATION_READ DSM_TOTAL_DURATION_WRITE DSM_TOTAL_DURATION_FREE DSM_TOTAL_DURATION_OTHER DSM_TOTAL_BUSY_TIME

The devstat(3) manpage claims that only is needed as a

2008-01-31T16:55:12Z

prerequisite for using this interface. However, the 'statinfo' struct actually references CPUSTATES from , so in fact it requires to compile. Use a nested include of to make the code match the docs. Reported by: Pietro Cerutti gahr | gahr.ch

Bump the shared library version number of all libraries that have not

2005-07-22T17:19:05Z

been bumped since RELENG_5. Reviewed by: ru Approved by: re (not needed for commit check but in principle...)

ARGH!

2003-03-18T17:05:27Z

Pointy hat to: phk

Commit ken@' changes to this file: Bump version and append new entries

2003-03-18T16:44:10Z

to stay backwards compatible.

Add more devstat calculations, mostly filling in holes, but also adding

2003-03-18T09:57:54Z

a couple of reqests: DSM_BUSY_PCT and DSM_QUEUE_LENGTH. I have no further plans for mutilating this API at this point in time, and will update the man-page to reflect current reality as the next thing. Reviewed by: ken

Run a revision of the devstat interface:

2003-03-15T21:59:06Z

Kernel: Change statistics to use the *uptime() timescale (ie: relative to boottime) rather than the UTC aligned timescale. This makes the device statistics code oblivious to clock steps. Change timestamps to bintime format, they are cheaper. Remove the "busy_count", and replace it with two counter fields: "start_count" and "end_count", which are updated in the down and up paths respectively. This removes the locking constraint on devstat. Add a timestamp argument to devstat_start_transaction(), this will normally be a timestamp set by the *_bio() function in bp->bio_t0. Use this field to calculate duration of I/O operations. Add two timestamp arguments to devstat_end_transaction(), one is the current time, a NULL pointer means "take timestamp yourself", the other is the timestamp of when this transaction started (see above). Change calculation of busy_time to operate on "the salami principle": Only when we are idle, which we can determine by the start+end counts being identical, do we update the "busy_from" field in the down path. In the up path we accumulate the timeslice in busy_time and update busy_from. Change the byte_* and num_* fields into two arrays: bytes[] and operations[]. Userland: Change the misleading "busy_time" name to be called "snap_time" and make the time long double since that is what most users need anyway, fill it using clock_gettime(CLOCK_MONOTONIC) to put it on the same timescale as the kernel fields. Change devstat_compute_etime() to operate on struct bintime. Remove the version 2 legacy interface: the change to bintime makes compatibility far too expensive. Fix a bug in systat's "vm" page where boot relative busy times would be bogus. Bump __FreeBSD_version to 500107 Review & Collaboration by: ken

Turn on WARNS?= 2 for libdevstat.

2001-09-23T23:03:23Z

Submitted by: "Sergey A. Osokin"

Implement compute_stats() in terms of devstat_compute_statistics(). This

2001-08-18T05:46:59Z

gets rid of the duplicated code in compute_stats(). Add a new DSM_SKIP statistic type for devstat_compute_statistics() that causes the subsequent variable argument to be skipped. Thanks to Sergey Osokin for coding up my idea/code fragment. Submitted by: "Sergey A. Osokin"

Add some features to libdevstat, and overhaul the interface a bit:

2001-08-04T18:25:48Z

1.) prefix all functions in the library with devstat_ (compatability functions are available for all functions that were chaned in an incompatible way, but are deprecated). 2.) Add a pointer to a kvm_t as the first argument to functions that used to get their information via sysctl; they behave the same as before when NULL is passed as this argument, otherwise, the information is obtained via libkvm using the supplied handle. 3.) Add a new function, devstat_compute_statistics(), that is intended to replace the old compute_stats() function. It offers more statistics data, and has a more flexible interface. libdevstat does now require libkvm; a library depedency is added, so that libkvm only needs to be explicitely specified for statically linked programs. The library major version number is bumped. Submitted by: Sergey A. Osokin , ken (3) Reviewed by: ken