Re: [PATCH v9 0/4] zram/zsmalloc promotion
From: Greg Kroah-Hartman
Date: Tue Dec 10 2013 - 21:16:51 EST
On Wed, Dec 11, 2013 at 11:09:59AM +0900, Minchan Kim wrote:
> Hello Greg,
>
> On Wed, Dec 11, 2013 at 11:04:35AM +0900, Minchan Kim wrote:
> > Zram is a simple pseudo block device which can keep data on
> > in-memory with compressed[1].
> >
> > It have been used for many embedded system for several years
> > One of significant usecase is in-memory swap device.
> > Because NAND which is very popular on most embedded device
> > is weak for frequent write without good wear-level
> > and slow I/O hurts system's responsiblity so zram is really
> > good choice to use memory efficiently.
> >
> > In previous trial, there was some argument[2] that zram has
> > similar goal with zswap so let's merge zram's functionality
> > into zswap via adding pseudo block device in zswap but I and
> > some people(At least, Hugh and Rik) believe it's not a good idea.
> > [2][3][4] and zswap might go writethrough model[5]. It makes
> > clear difference zram and zswap.
> >
> > Zram itself is simple/well-designed/good abstraciton so it has
> > clear market(ex, Android, TV, ChromeOS, some Linux distro) which
> > is never niche. :)
> >
> > Another zram-blk's usecase is following as.
> > The admin can use it as tmpfs so it could help small memory system.
> > The tmpfs is never good solution for swapless embedded system.
> >
> > Patch 1 adds new Kconfig for zram to use page table method instead
> > of copy.
> >
> > Patch 2 adds more comment for zsmalloc.
> >
> > Patch 3 moves zsmalloc under mm.
> >
> > Patch 4 moves zram from driver/staging to driver/blocks, finally.
>
> Patch 1(suggested by Andrew Morton) and 2(Just comment to make review easy)
> are prepartion for promotion so I hope it could be merged into your staging
> regardless of allowing promotion at the moment.
Sure, I'll be glad to do so, thanks for letting me know.
greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/