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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-08 19:04:12 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-08 19:04:12 -0500
commit820828bffeb11eee41e197a0c9be1b72afa37482 (patch)
treee2ea7533a44893f796cc9d920656b616e712e0dc /scripts/basic
parent6b2912cedc238c984e6a4039836ed9c911121076 (diff)
parent5a3840a470c41ec0b85cd36ca80370330656b163 (diff)
Merge tag 'powerpc-5.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman: "Just two fixes, both going to stable. - Our support for split pmd page table lock had a bug which could lead to a crash on mremap() when using the Radix MMU (Power9 only). - A fix for the PAPR SCM driver (nvdimm) we added last release, which had a bug where we might mis-handle a hypervisor response leading to us failing to attach the memory region. Thanks to: Aneesh Kumar K.V, Oliver O'Halloran" * tag 'powerpc-5.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/papr_scm: Use the correct bind address powerpc/radix: Fix kernel crash with mremap()
Diffstat (limited to 'scripts/basic')
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generated by cgit v1.2.2 (git 2.25.0) at 2026-04-06 19:43:39 -0400
'n118' href='#n118'>118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 
Version 15 of schedstats dropped counters for some sched_yield:
yld_exp_empty, yld_act_empty and yld_both_empty. Otherwise, it is
identical to version 14.

Version 14 of schedstats includes support for sched_domains, which hit the
mainline kernel in 2.6.20 although it is identical to the stats from version
12 which was in the kernel from 2.6.13-2.6.19 (version 13 never saw a kernel
release).  Some counters make more sense to be per-runqueue; other to be
per-domain.  Note that domains (and their associated information) will only
be pertinent and available on machines utilizing CONFIG_SMP.

In version 14 of schedstat, there is at least one level of domain
statistics for each cpu listed, and there may well be more than one
domain.  Domains have no particular names in this implementation, but
the highest numbered one typically arbitrates balancing across all the
cpus on the machine, while domain0 is the most tightly focused domain,
sometimes balancing only between pairs of cpus.  At this time, there
are no architectures which need more than three domain levels. The first
field in the domain stats is a bit map indicating which cpus are affected
by that domain.

These fields are counters, and only increment.  Programs which make use
of these will need to start with a baseline observation and then calculate
the change in the counters at each subsequent observation.  A perl script
which does this for many of the fields is available at

    http://eaglet.rain.com/rick/linux/schedstat/

Note that any such script will necessarily be version-specific, as the main
reason to change versions is changes in the output format.  For those wishing
to write their own scripts, the fields are described here.

CPU statistics
--------------
cpu<N> 1 2 3 4 5 6 7 8 9

First field is a sched_yield() statistic:
     1) # of times sched_yield() was called

Next three are schedule() statistics:
     2) This field is a legacy array expiration count field used in the O(1)
	scheduler. We kept it for ABI compatibility, but it is always set to zero.
     3) # of times schedule() was called
     4) # of times schedule() left the processor idle

Next two are try_to_wake_up() statistics:
     5) # of times try_to_wake_up() was called
     6) # of times try_to_wake_up() was called to wake up the local cpu

Next three are statistics describing scheduling latency:
     7) sum of all time spent running by tasks on this processor (in jiffies)
     8) sum of all time spent waiting to run by tasks on this processor (in
        jiffies)
     9) # of timeslices run on this cpu


Domain statistics
-----------------
One of these is produced per domain for each cpu described. (Note that if
CONFIG_SMP is not defined, *no* domains are utilized and these lines
will not appear in the output.)

domain<N> <cpumask> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

The first field is a bit mask indicating what cpus this domain operates over.

The next 24 are a variety of load_balance() statistics in grouped into types
of idleness (idle, busy, and newly idle):

     1) # of times in this domain load_balance() was called when the