I am trying to read the /proc/timer_list file.But the issue i am having is that, there are several number of jiffies per CPU.So i am confused which value i should use to calculate seconds per jiffy.
**Here i have included what the entities inside /proc/timer_list represents.**
读取此文件的命令：-
cat/proc/timer_list
/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.
+
+ This document covers only the version of /proc/timer_list
+ located in the kernel sources to which it is attached.
+ Documentation for previous (and later) versions of
+ /proc/timer_list is to be found (if they exist) in the
+ kernel sources of those earlier (or later) kernels.
+
+ Section Overview
+ ----------------
+ The file contains several somewhat independent sections.
+
+ The first section contains a few lines of global info:
+ 1 - Timer List Version: File revision.
+ 2 - HRTIMER_MAX_CLOCK_BASES: number of clock types that
+ support high resolution timers.
+ 3 - now at x nsecs: number of 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 on this CPU:
+ 1 - clock ID: 0 == CLOCK_REALTIME, 1 == CLOCK_MONOTONIC
+ 2 - base: kernel address of this clock's
+ hrtimer_clock_base structure.
+ 3 - resolution: resolution of this clock.
+ 4 - get_time: name of kernel function used to fetch
+ time from this clock.
+ 5 - offset: difference, in nsecs, between this clock
+ and the reference clock for this clock.
+ Under each of these clocks is, in turn, a display of all
+ the active high resolution timers queued to that clock.
+ These are the lines beginning with '#' and are described
+ in detail later in this document.
+
+ The contents of per-CPU hrtimer data fields not
+ associated with a particular cpu clock (ie, shared by
+ both clocks or not associated with any clock). These
+ are: expires_next, hres_active, nr_event, nohz_mode, all
+ things idle_*, tick_stopped, last_jiffies, next_jiffies.
+ The above are field names from 'struct tick_sched' and
+ 'struct hrtimer_cpu_base', documentation for these may
+ be found in the kernel DocBook.
+
+ A display of low resolution (ie, jiffie) timer wheel
+ data. These are prefixed by the lines:
+ 1 - base: kernel virtual address of the timer wheel
+ data structure (struct tvec_base) for this cpu.
+ 2 - running timer: kernel virtual address of the
+ expired timer being processed, NULL if none.
+ 3 - timer_jiffies: what this wheel considers to
+ be the current time, will be == jiffies or
+ will lag it by a tick or two if it has not
+ caught up with the current time.
+ Also under this section is a display, one per line, of
+ each active jiffie timer queued to this CPU. These are
+ the 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 of tick devices:
+ hpet, pit, lapic. All but the first two lines display
+ fields corresponding to structure elements from 'struct
+ clock_event_device', documentation for which can be found
+ in the kernel Docbook. The first two lines are:
+ 1 - mode: 0 == periodic timer, 1 == one-shot timer
+ 2 - is 'Per CPU device' or is 'Broadcast device'
+
+ 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 - number of 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