src/lib/libdevstat/devstat.h, branch release/13.1.0

lib: further adoption of SPDX licensing ID tags.

2017-11-26T02:00:33Z

Mainly focus on files that use BSD 2-Clause license, however the tool I was using mis-identified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts.

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"