mirror-linux/include
Mikulas Patocka 5b18b5a737 block: delete part_round_stats and switch to less precise counting
We want to convert to per-cpu in_flight counters.

The function part_round_stats needs the in_flight counter every jiffy, it
would be too costly to sum all the percpu variables every jiffy, so it
must be deleted. part_round_stats is used to calculate two counters -
time_in_queue and io_ticks.

time_in_queue can be calculated without part_round_stats, by adding the
duration of the I/O when the I/O ends (the value is almost as exact as the
previously calculated value, except that time for in-progress I/Os is not
counted).

io_ticks can be approximated by increasing the value when I/O is started
or ended and the jiffies value has changed. If the I/Os take less than a
jiffy, the value is as exact as the previously calculated value. If the
I/Os take more than a jiffy, io_ticks can drift behind the previously
calculated value.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
..
acpi
asm-generic s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
clocksource
crypto
drm drm, i915, amdgpu, bridge + core quirk 2018-11-02 10:58:20 -07:00
dt-bindings This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00
keys
kvm
linux block: delete part_round_stats and switch to less precise counting 2018-12-10 08:30:37 -07:00
math-emu
media media: Use wait_queue_head_t for media_request 2018-11-20 12:53:23 -05:00
memory
misc
net neighbour: Avoid writing before skb->head in neigh_hh_output() 2018-12-07 16:24:40 -08:00
pcmcia
ras
rdma
scsi scsi: Fix a harmless double shift bug 2018-12-07 22:27:01 -07:00
soc
sound ALSA: pcm: Fix interval evaluation with openmin/max 2018-11-29 12:05:19 +01:00
target
trace While rewriting the function graph tracer, I discovered a design flaw that 2018-11-30 09:32:34 -08:00
uapi Linux 4.20-rc6 2018-12-09 17:45:40 -07:00
video
xen Revert "xen/balloon: Mark unallocated host memory as UNUSABLE" 2018-11-29 17:53:31 +01:00