Document /proc/timer_list ABI. This documents all of /timer_list, including the extension adding jiffie timers, as proposed in the patch:
[PATCH] Display active jiffie timers in /proc/timer_list, v2 Signed-off-by: Joe Korty <[EMAIL PROTECTED]> Index: 2.6.28-rc6/Documentation/ABI/stable/procfs-timer_list =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ 2.6.28-rc6/Documentation/ABI/stable/procfs-timer_list 2008-11-26 15:55:04.000000000 -0500 @@ -0,0 +1,96 @@ +What: /proc/timer_list +Date: November 2008 +Contact: Ingo Molnar <[EMAIL PROTECTED]> + Thomas Gleixner <[EMAIL PROTECTED]> + Joe Korty <[EMAIL PROTECTED]> +Revision-Rate: Moderate +At-Revision: 0.5 +Description: + /proc/timer_list displays most everything about every kind + of timer, and some things about time too. + + The contents of this file should be expected to change, + as the data displayed corresponds directly to various + kernel-internal data structures. For this reason, the first + line contains the file revision. It is the responsibility + of this file's maintainers to bump the revision each time a + kernel is released having incompatible changes in this file. + + Section Overview + ---------------- + The file contains several somewhat independent sections. + + The first section contains a few lines of global info. + Examples: file version id, #clock types in the kernel, + #nsecs since boot. + + The second section is organized per-cpu. Each cpu subsection + in turn contains several sub-subsections which are, in order + of appearance: + + The contents of the data structures associated with each + clock (CLOCK_REALTIME, CLOCK_MONOTONIC, etc) on this cpu. + Examples: base, index, resolution, get_timer, offset. + Under each of these clocks is, in turn, a display of all + the active high resolution timers queued to that clock. + Example: all lines beginning with '#'. + + The contents of per-cpu timer data fields not associated + with a particular clock type (ie, shared by both clocks or + not associated with any clock). Examples: expires_next, + hres_active, nr_event, nohz_mode, all things idle_*, + tick_stopped, last_jiffies, next_jiffies. + + A display of low resolution (ie, jiffie) timer wheel + data. Examples: base, running_timer, timer_jiffies. + Also under this section is a display, one per line, of + each active jiffie timer queued to this cpu. Examples: + All lines under an 'active jiffie timers' section that + begin with a number. + + The third and final section describes each 'tick device' + known to the kernel. A tick device is a piece of hardware + capable of generating periodic and/or one shot interrupts + under software control, and thus is capable of generating + the interrupts needed to expire the various active timers at + their given expiration times. Examples: hpet, pit, lapic. + + Hires Timer Layout + ------------------ + High resolution timers are displayed on lines that begin + with a '#' and always appear under one of the many sections + labeled 'active timers'. There is an 'active timers' + section for every cpu and every clock. + + The fields of a hrtimer, spread out over two lines, are: + + line 1 fields: + 1 - unique hrtimer index (#0, #1, #2, etc) + 2 - kernel address of the hrtimer data structure + in question + 3 - function to be called when timer expires + 4 - timer state (eg, S:01), avail states, OR-able: + 0 - inactive + 1 - enqueued + 2 - callback + 4 - pending + 8 - migrate + 5 - function which created the timer + 6 - process name & pid which created the timer + + line 2 fields: + 1 - absolute expiration time, range format (start - end) + 2 - relative expiration time, range format (start - end) + + Lowres Timer Layout + ------------------- + Low resolution timers are displayed one-per-line under + sections labeled 'active jiffie timers'. There is one such + section per cpu. A lowres timer has the following fields: + + 1 - #jiffies remaining until timer expires + 2 - function to be called on expiration + 3 - data value to be given to the above function on + expiration + 4 - function which created this timer + 5 - name & pid of the process that created this timer -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
