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

From: Chao Peng
Date: Mon Mar 27 2017 - 05:27:50 EST


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