On Mon, Mar 27, 2017 at 1:47 PM, Michal Marek <[email protected]> wrote:
> Dne 27.3.2017 v 09:58 Sebastian Andrzej Siewior napsal(a):
>> On 2017-03-24 13:35:40 [+0800], Chao Peng wrote:
>>>
>>>>>> kernel kernel size time in decompress_kernel
>>>>>> compressed (gzip) 3.3M 53ms
>>>>>> uncompressed 14M 3ms
>>>>>
>>> Exactly, LZ4 is the fastest. It takes 16ms to complete the
>>> decompression. Still sounds a little longer when compared to
>>> uncompressed kernel.
>>
>> Are we seriously talking here about one-time improvement of 13ms
>> boot time?
>
> If the use case is launching new VM instances continuously, then
> compressing the kernel image is about as useful as compressing /bin/bash.
I guess the next step would be to use CONFIG_XIP_KERNEL on x86,
which requires an uncompressed kernel but has the additional advantage
of sharing the read-only sections of the kernel image across virtual
machines, resulting in better RAM and cache usage.
Arnd
