The main goal of the patch is to effectively cap the disk I/O speed or counts
of one single VM.It is only one draft, so it unavoidably has some drawbacks, if
you catch them, please let me know.
The patch will mainly introduce one block I/O throttling algorithm, one timer
and one block queue for each I/O limits enabled drive.
When a block request is coming in, the throttling algorithm will check if its
I/O rate or counts exceed the limits; if yes, then it will enqueue to the block
queue; The timer will handle the I/O requests in it.
Some available features follow as below:
(1) global bps limit.
-drive bps=xxx in bytes/s
(2) only read bps limit
-drive bps_rd=xxx in bytes/s
(3) only write bps limit
-drive bps_wr=xxx in bytes/s
(4) global iops limit
-drive iops=xxx in ios/s
(5) only read iops limit
-drive iops_rd=xxx in ios/s
(6) only write iops limit
-drive iops_wr=xxx in ios/s
(7) the combination of some limits.
-drive bps=xxx,iops=xxx
Known Limitations:
(1) #1 can not coexist with #2, #3
(2) #4 can not coexist with #5, #6
(3) When bps/iops limits are specified to a small value such as 511 bytes/s,
this VM will hang up. We are considering how to handle this senario.
Zhi Yong Wu (3):
v4: fix memory leaking based on ryan's feedback.
The cmd support for QEMU block I/O throttling
The support for block queue
The support for queue timer and throttling algorithm
v3: Added the code for extending slice time, and modified the method to
compute wait time for the timer.
v2: The codes V2 for QEMU disk I/O limits.
Modified the codes mainly based on stefan's comments.
v1: Submit the codes for QEMU disk I/O limits.
Only a code draft.
Makefile.objs | 2 +-
block.c | 302 +++++++++++++++++++++++++++++++++++++++++++++++++++--
block.h | 1 -
block/blk-queue.c | 122 +++++++++++++++++++++
block/blk-queue.h | 71 +++++++++++++
block_int.h | 29 +++++
blockdev.c | 22 ++++
qemu-config.c | 24 ++++
qemu-option.c | 17 +++
qemu-option.h | 1 +
qemu-options.hx | 1 +
11 files changed, 582 insertions(+), 10 deletions(-)
create mode 100644 block/blk-queue.c
create mode 100644 block/blk-queue.h
--
1.7.2.3
