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[Qemu-block] [PATCH 2/2] throttle: Use bs->throttle_state instead of bs-
From: |
Alberto Garcia |
Subject: |
[Qemu-block] [PATCH 2/2] throttle: Use bs->throttle_state instead of bs->io_limits_enabled |
Date: |
Wed, 4 Nov 2015 15:15:36 +0200 |
There are two ways to check for I/O limits in a BlockDriverState:
- bs->throttle_state: if this pointer is not NULL, it means that this
BDS is member of a throttling group, its ThrottleTimers structure
has been initialized and its I/O limits are ready to be applied.
- bs->io_limits_enabled: if true it means that the throttle_state
pointer is valid _and_ the limits are currently enabled.
The latter is used in several places to check whether a BDS has I/O
limits configured, but what it really checks is whether requests
are being throttled or not. For example, io_limits_enabled can be
temporarily set to false in cases like bdrv_read_unthrottled() without
otherwise touching the throtting configuration of that BDS.
This patch replaces bs->io_limits_enabled with bs->throttle_state in
all cases where what we really want to check is the existence of I/O
limits, not whether they are currently enabled or not.
Signed-off-by: Alberto Garcia <address@hidden>
---
block.c | 6 +++---
block/qapi.c | 2 +-
blockdev.c | 4 ++--
include/block/block_int.h | 5 ++++-
4 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/block.c b/block.c
index e9f40dc..2f433d6 100644
--- a/block.c
+++ b/block.c
@@ -1901,7 +1901,7 @@ void bdrv_close(BlockDriverState *bs)
}
/* Disable I/O limits and drain all pending throttled requests */
- if (bs->io_limits_enabled) {
+ if (bs->throttle_state) {
bdrv_io_limits_disable(bs);
}
@@ -3706,7 +3706,7 @@ void bdrv_detach_aio_context(BlockDriverState *bs)
baf->detach_aio_context(baf->opaque);
}
- if (bs->io_limits_enabled) {
+ if (bs->throttle_state) {
throttle_timers_detach_aio_context(&bs->throttle_timers);
}
if (bs->drv->bdrv_detach_aio_context) {
@@ -3742,7 +3742,7 @@ void bdrv_attach_aio_context(BlockDriverState *bs,
if (bs->drv->bdrv_attach_aio_context) {
bs->drv->bdrv_attach_aio_context(bs, new_context);
}
- if (bs->io_limits_enabled) {
+ if (bs->throttle_state) {
throttle_timers_attach_aio_context(&bs->throttle_timers, new_context);
}
diff --git a/block/qapi.c b/block/qapi.c
index ec0f513..89d4274 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -64,7 +64,7 @@ BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs,
Error **errp)
info->backing_file_depth = bdrv_get_backing_file_depth(bs);
info->detect_zeroes = bs->detect_zeroes;
- if (bs->io_limits_enabled) {
+ if (bs->throttle_state) {
ThrottleConfig cfg;
throttle_group_get_config(bs, &cfg);
diff --git a/blockdev.c b/blockdev.c
index 8b8bfa9..a418fbf 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2161,14 +2161,14 @@ void qmp_block_set_io_throttle(const char *device,
int64_t bps, int64_t bps_rd,
if (throttle_enabled(&cfg)) {
/* Enable I/O limits if they're not enabled yet, otherwise
* just update the throttling group. */
- if (!bs->io_limits_enabled) {
+ if (!bs->throttle_state) {
bdrv_io_limits_enable(bs, has_group ? group : device);
} else if (has_group) {
bdrv_io_limits_update_group(bs, group);
}
/* Set the new throttling configuration */
bdrv_set_io_limits(bs, &cfg);
- } else if (bs->io_limits_enabled) {
+ } else if (bs->throttle_state) {
/* If all throttling settings are set to 0, disable I/O limits */
bdrv_io_limits_disable(bs);
}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 3ceeb5a..533500e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -390,7 +390,10 @@ struct BlockDriverState {
/* number of in-flight serialising requests */
unsigned int serialising_in_flight;
- /* I/O throttling */
+ /* I/O throttling.
+ * throttle_state tells us if this BDS has I/O limits configured.
+ * io_limits_enabled tells us if they are currently being
+ * enforced, but it can be temporarily set to false */
CoQueue throttled_reqs[2];
bool io_limits_enabled;
/* The following fields are protected by the ThrottleGroup lock.
--
2.6.2