On 2024/1/26 10:41, Chunhai Guo wrote:
On 2024/1/22 15:42, Chunhai Guo wrote:
On 2024/1/22 12:37, Gao Xiang wrote:
[你通常不会收到来自 hsiang...@linux.alibaba.com 的电子邮件。请访问 
https://aka.ms/LearnAboutSenderIdentification,以了解这一点为什么很重要]

On 2024/1/22 11:49, Chunhai Guo wrote:
On 2024/1/22 10:07, Gao Xiang wrote:
[你通常不会收到来自 hsiang...@linux.alibaba.com 的电子邮件。请访问 
https://aka.ms/LearnAboutSenderIdentification,以了解这一点为什么很重要]

On 2024/1/20 22:55, Chunhai Guo wrote:
Even with inplace decompression, sometimes extra temporary buffers are
still needed for decompression.  In low-memory scenarios, it would be
better to try to allocate with GFP_NOWAIT on readahead first. That can
help reduce the time spent on page allocation under memory pressure.

There is an average reduction of 21% in page allocation time under
It would be better to add a table to show the absolute numbers too
(like what you did in the global pool commit.)  If it's possible, there
is no need to send a update version for this, just reply the updated
commit message and I will update the commit manually.
The table below shows detailed numbers. The reduction I mentioned before
was not accurate enough. Please help correct the improvement from 21% to
20.21%.


+--------------+----------------+---------------+---------+
|              | w/o GFP_NOWAIT | w/ GFP_NOWAIT |  diff   |
+--------------+----------------+---------------+---------+
| Average (ms) |     3364       |      2684     | -20.21% |
+--------------+----------------+---------------+---------+
Did it test without the 16k sliding window change?
https://lore.kernel.org/linux-erofs/69711d55-f7a2-420b-9ba8-fa2921f66...@vivo.com
The result is tested with 64k sliding window change.

Could you benchmark these two optimizations together to
show the extreme optimized case without a global pool?
With a new table if possible? I will add this to
the commit message too.

OK. I will reply to this email when the benchmark is finished.

The benchmark has been completed and the table below shows that there is
an average 52.14% reduction in page allocation time with these two
optimizations.

+--------------+----------------+---------------+---------+ | | 64k
window | 16k window | | | | w/o GFP_NOWAIT | w/ GFP_NOWAIT | diff |
+--------------+----------------+---------------+---------+ | Average
(ms) | 3364 | 1610 | -52.14% |
+--------------+----------------+---------------+---------+

Table below summarizes the results of these three benchmarks.

+--------------+----------------+----------------+---------------+---------------+
|              |   64k window   |   16k window   |   64k window  | 16k
window  |
|              | w/o GFP_NOWAIT | w/o GFP_NOWAIT | w/ GFP_NOWAIT | w/
GFP_NOWAIT |
+--------------+----------------+----------------+---------------+---------------+
| Average (ms) |     3364       |      2079      |      2684 |
1610     |
+--------------+----------------+----------------+---------------+---------------+
|     diff     |                |     -38.19%    |     -20.81% |
-52.14%   |
+--------------+----------------+----------------+---------------+---------------+


The tables shows in a mess, could you just list the
numbers so I could refine this?

Thanks,
Gao Xiang

Reply via email to