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author | Tejun Heo <tj@kernel.org> | 2012-03-19 15:10:58 -0700 |
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committer | Jens Axboe <axboe@kernel.dk> | 2012-03-20 12:47:47 +0100 |
commit | 598971bfbdfdc8701337dc1636c7919c44699914 (patch) | |
tree | 3de33d5059ce3a0cf77a9735804335f9264b7c08 /fs/eventfd.c | |
parent | abede6da27d9bd62ea9512830c83e32b3ee1104c (diff) | |
download | op-kernel-dev-598971bfbdfdc8701337dc1636c7919c44699914.zip op-kernel-dev-598971bfbdfdc8701337dc1636c7919c44699914.tar.gz |
cfq: don't use icq_get_changed()
cfq caches the associated cfqq's for a given cic. The cache needs to
be flushed if the cic's ioprio or blkcg has changed. It is currently
done by requiring the changing action to set the respective
ICQ_*_CHANGED bit in the icq and testing it from cfq_set_request(),
which involves iterating through all the affected icqs.
All cfq wants to know is whether ioprio and/or blkcg have changed
since the last flush and can be easily achieved by just remembering
the current ioprio and blkcg ID in cic.
This patch adds cic->{ioprio|blkcg_id}, updates all ioprio users to
use the remembered value instead, and updates cfq_set_request() path
such that, instead of using icq_get_changed(), the current values are
compared against the remembered ones and trigger appropriate flush
action if not. Condition tests are moved inside both _changed
functions which are now named check_ioprio_changed() and
check_blkcg_changed().
ioprio.h::task_ioprio*() can't be used anymore and replaced with
open-coded IOPRIO_CLASS_NONE case in cfq_async_queue_prio().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/eventfd.c')
0 files changed, 0 insertions, 0 deletions