5.4-stable review patch. If anyone has any objections, please let me know.
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From: Tejun Heo tj@kernel.org
[ Upstream commit db84a72af6be422abf2089a5896293590dda5066 ]
__propagate_weights() currently expects the callers to clamp inuse within [1, active], which is needlessly fragile. The inuse adjustment logic is going to be revamped, in preparation, let's make __propagate_weights() clamp inuse on entry.
Also, make it avoid weight updates altogether if neither active or inuse is changed.
Signed-off-by: Tejun Heo tj@kernel.org Signed-off-by: Jens Axboe axboe@kernel.dk Stable-dep-of: 57e420c84f9a ("blk-iocost: Avoid using clamp() on inuse in __propagate_weights()") Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk-iocost.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index e7d5aafa5e99..75eb90b3241e 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -907,7 +907,10 @@ static void __propagate_active_weight(struct ioc_gq *iocg, u32 active, u32 inuse
lockdep_assert_held(&ioc->lock);
- inuse = min(active, inuse); + inuse = clamp_t(u32, inuse, 1, active); + + if (active == iocg->active && inuse == iocg->inuse) + return;
for (lvl = iocg->level - 1; lvl >= 0; lvl--) { struct ioc_gq *parent = iocg->ancestors[lvl];