Possible stable fix for decompressor speed

Possible stable fix for decompressor speed

[Mark Brown]

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The changes in patch 1431574a1c4c (lib/decompressors: fix "no limit"
output buffer length) avoid doing decompression a byte at a time when
decompressing into high physical addresses using a small, well isolated
change.  The patch can give a very noticable improvement in kernel boot
times on affected systems, for example with one ARM system this reduces
the total time to boot the kernel by more than a third.

Would you consider this patch for stable?  It doesn't quite fit within
the criteria but you've indicated in the past that such isolated and
well supported changs can be acceptable anyway.  If it's not OK for
stable it seems like it should be a good candidate for LTSI.

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Re: Possible stable fix for decompressor speed

[Greg Kroah-Hartman]

On Tue, Jan 28, 2014 at 04:14:28PM +0000, Mark Brown wrote:
> The changes in patch 1431574a1c4c (lib/decompressors: fix "no limit"
> output buffer length) avoid doing decompression a byte at a time when
> decompressing into high physical addresses using a small, well isolated
> change.  The patch can give a very noticable improvement in kernel boot
> times on affected systems, for example with one ARM system this reduces
> the total time to boot the kernel by more than a third.
> 
> Would you consider this patch for stable?  It doesn't quite fit within
> the criteria but you've indicated in the past that such isolated and
> well supported changs can be acceptable anyway.  If it's not OK for
> stable it seems like it should be a good candidate for LTSI.

It's a one-line change that seems well tested and provides a noticed
speedup, so yes, I can take it for the 3.10-stable tree, thanks.

greg k-h

Re: Possible stable fix for decompressor speed

[Luis Henriques]

On Tue, Jan 28, 2014 at 04:14:28PM +0000, Mark Brown wrote:
> The changes in patch 1431574a1c4c (lib/decompressors: fix "no limit"
> output buffer length) avoid doing decompression a byte at a time when
> decompressing into high physical addresses using a small, well isolated
> change.  The patch can give a very noticable improvement in kernel boot
> times on affected systems, for example with one ARM system this reduces
> the total time to boot the kernel by more than a third.
> 
> Would you consider this patch for stable?  It doesn't quite fit within
> the criteria but you've indicated in the past that such isolated and
> well supported changs can be acceptable anyway.  If it's not OK for
> stable it seems like it should be a good candidate for LTSI.

Thanks Mark, I'm queuing this for the 3.5 and the 3.11 kernels as well.

Cheers,
--
Luis