Re: [PATCH] x86/boot: Support uncompressed kernel

[Chao Peng]

On Mon, 2017-03-27 at 09:58 +0200, Sebastian Andrzej Siewior wrote:
> On 2017-03-24 13:35:40 [+0800], Chao Peng wrote:
> > 
> > 
> > > 
> > > > 
> > > > > 
> > > > > ÂÂÂÂkernelÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂkernel sizeÂÂÂÂtime in
> > > > > decompress_kernel
> > > > > ÂÂÂÂcompressed (gzip)ÂÂÂÂ3.3MÂÂÂÂÂÂÂÂÂÂÂ53ms
> > > > > ÂÂÂÂuncompressedÂÂÂÂÂÂÂÂÂ14MÂÂÂÂÂÂÂÂÂÂÂÂ3ms
> > > > 
> > 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?

The usage model for us is to lunch kernel in virtual machine and there
will be thousands of instances lunched and shutdowned/re-lunched
frequently, so every single million-second helps. And 13ms means 20%
improvement to our existing optimization (the other part besides
decompression is optimized to ~40ms).

Chao
> 
> > 
> > Chao
> 
> Sebastian