回复: [edk2-devel] Multithreaded compression with LZMA2

["gaoliming" <gaoliming@byosoft.com.cn>]

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Daniel:

 Can you provide the compressed image size? And, what image is used to be
compressed? Is it the generated FV image?

 

Thanks

Liming

发件人: bounce+27952+68159+4905953+8761045@groups.io
<bounce+27952+68159+4905953+8761045@groups.io> 代表 Andrew Fish via
groups.io
发送时间: 2020年12月2日 11:37
收件人: devel@edk2.groups.io; daniel.schaefer@hpe.com
抄送: derek.lin2@hpe.com
主题: Re: [edk2-devel] Multithreaded compression with LZMA2

 

 





On Dec 1, 2020, at 6:59 PM, Daniel Schaefer <daniel.schaefer@hpe.com
<mailto:daniel.schaefer@hpe.com> > wrote:

 

Hi everyone,

I'm looking into how to speed up the build process and noticed that our
build
uses LZMA to encrypt the main firmware volume. Since it's quite big it takes
a
while but only uses one CPU thread.

LZMA2 is a version of LZMA which can be multi-threaded and achieve much
faster
compression times. I did a quick benchmark using the `xz` command-line tool,
which uses a modified version of the LZMA SDK that EDK2 uses. The results
are:

Uncompressed size: 64M

| Algo  | Comp Time | Decomp Time | Size | Threads |
| ----- | --------- | ----------- | ---- | ------- |
| LZMA  |    19.67s |        0.9s | 9.1M |       1 |
| LZMA2 |    20.11s |        1.2s | 9.2M |       1 |
| LZMA2 |     8.31s |        1.0s | 9.4M |       4 |

Using those commands:

time xz --format=lzma testfile
time unlzma testfile.lzma

time xz --lzma2 testfile
time unxz testfile.xz

time xz -T4 --lzma2 testfile
time unxz testfile.xz

This is quite a significant improvement of build time, while decompression
time
and size only slightly increase. If that's a concern, then LZMA2 could be
used
for development only.

I haven't investigated the details of how to support this in the code but it
appears to be a simple change, since the LZMA SDK that we use already
supports
LZMA2.

What do you think?



 

Interesting idea. What OS did you use? I tried this on macOS on some larger
FVs and I did not see much difference? I tried a 17.5 MiB FV and it was
around 3 seconds both ways. 

 

Maybe it would be worth while seeing how it works on various systems? I
guess it might be data set related? 

 

Thanks,

 

Andrew Fish





Thanks,
Daniel





 




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