On Mon, Jun 13, 2016 at 11:11:00AM +0200, Vitaly Wool wrote: > Den 8 juni 2016 6:33 em skrev "Dan Streetman" <[email protected]>: > > > > On Wed, Jun 8, 2016 at 5:39 AM, Geliang Tang <[email protected]> > wrote: > > > This patch adds zpool support for zram, it will allow us to use both > > > the zpool api and directly zsmalloc api in zram. > > > > besides the problems below, this was discussed a while ago and I > > believe Minchan is still against it, as nobody has so far shown what > > the benefit to zram would be; zram doesn't need the predictability, or > > evictability, of zbud or z3fold. > > > Right. > > > > Geliang, I cannot ack without any *detail* that what's the problem of > > zram/zsmalloc, why we can't fix it in zsmalloc itself. > > The zbud and zsmalloc is otally different design to aim different goal > > determinism vs efficiency so you can choose what you want between > > zswap > > and zram rather than mixing the features. > > I'd also probably Cc Vitaly Wool on this > > Well, I believe I have something to say here. z3fold is generally faster > than zsmalloc which makes it a better choice for zram sometimes, e.g. when > zram device is used for swap. Also, z3fold and zbud do not require MMU so > zram over these can be used on small Linux powered MMU-less IoT devices, as > opposed to the traditional zram over zsmalloc. Otherwise I do agree with > Dan. > > > > > It doesn't make sense for zram to conditionally use zpool; either it > > uses it and thus has 'select ZPOOL' in its Kconfig entry, or it > > doesn't use it at all. > > > > > +#endif > > > > first, no. this obviously makes using zpool in zram completely pointless. > > > > second, did you test this? the pool you're passing is the zpool, not > > the zs_pool. quite bad things will happen when this code runs. There > > is no way to get the zs_pool from the zpool object (that's the point > > of abstraction, of course). > > > > The fact zpool doesn't have these apis (currently) is one of the > > reasons against changing zram to use zpool. > >
Thank you all for your reply. I updated the patch and I hope this is better. Geliang Tang (1): zram: update zram to use zpool drivers/block/zram/Kconfig | 3 ++- drivers/block/zram/zram_drv.c | 59 ++++++++++++++++++++++--------------------- drivers/block/zram/zram_drv.h | 4 +-- mm/zsmalloc.c | 12 +++++---- 4 files changed, 41 insertions(+), 37 deletions(-) -- 2.5.5
