Hi,
在 2024/12/10 2:11, Bart Van Assche 写道:
On 12/9/24 7:55 PM, Yu Kuai wrote:
From: Yu Kuai <yukuai3@xxxxxxxxxx>
Currently, shallow_depth is used by bfq, kyber and mq-deadline, they both
pass in the value for the whole sbitmap, while sbitmap treate the value
for just one word. Which means, shallow_depth never work as expected,
and there really is no such functional tests to covert it.
treate -> treats
The above text is incorrect. I have verified that shallow_depth
restricts the queue depth of asynchronous requests for mq-deadline if it
is reduced from its default value. The function dd_word_to_depth() in
mq-deadline converts the value written into the sysfs attribute into a
value that is appropriate for the sbitmap implementation.
Hi,
please notice that patch 1 is reverted in this set, which means
dd_word_to_depth() is not existed. :)
And for patch 1, dd_word_to_depth() doesn't(and can't) handle the last
word, for the case that avaliable bits in the last word is less than
1 << sb->shift. So, in fact it's not convert to the appropriate value.
That being said, it seems like a good idea to me to modify how the
sbitmap code interprets 'shallow_depth'.
Good to know!
Thanks,
Kuai
Thanks,
Bart.
.
