Re: [PATCH 7/8] zswap: add to mm/

2013-01-07 Thread Seth Jennings
On 01/04/2013 04:45 PM, Dan Magenheimer wrote: >> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] >> Subject: Re: [PATCH 7/8] zswap: add to mm/ >> >> On 01/03/2013 04:33 PM, Dan Magenheimer wrote: >>>> From: Seth Jennings [mailto:sjenn...@linux.vnet.

RE: [PATCH 7/8] zswap: add to mm/

2013-01-04 Thread Dan Magenheimer
> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > On 01/03/2013 04:33 PM, Dan Magenheimer wrote: > >> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] > >> > >> However, once the flushing code

RE: [PATCH 7/8] zswap: add to mm/

2013-01-04 Thread Dan Magenheimer
> From: Dave Chinner [mailto:da...@fromorbit.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ Hi Dave -- Thanks for your continued helpful feedback and expertise! > > Given the above, do you think either compressed-anonymous-pages or > > compressed-pagecache-pages are suita

Re: [PATCH 7/8] zswap: add to mm/

2013-01-04 Thread Seth Jennings
On 01/03/2013 08:30 PM, Dave Chinner wrote: >>> And so the two subsystems need different reclaim implementations. >>> > > And, well, that's exactly what we have shrinkers for - implmenting >>> > > subsystem specific reclaim policy. The shrinker infrastructure is >>> > > responsible for them keeping

Re: [PATCH 7/8] zswap: add to mm/

2013-01-04 Thread Seth Jennings
On 01/03/2013 04:33 PM, Dan Magenheimer wrote: >> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] >> >> However, once the flushing code was introduced and could free an entry >> from the zswap_fs_store() path, it became necessary to add a per-entry >> refcount to make sure that the entry i

Re: [PATCH 7/8] zswap: add to mm/

2013-01-03 Thread Dave Chinner
On Thu, Jan 03, 2013 at 02:37:01PM -0800, Dan Magenheimer wrote: > > From: Dave Chinner [mailto:da...@fromorbit.com] > > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > > > > > OK, I have suitably proven how little I know about slab > and have received some need

RE: [PATCH 7/8] zswap: add to mm/

2013-01-03 Thread Dan Magenheimer
> From: Dave Chinner [mailto:da...@fromorbit.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > OK, I have suitably proven how little I know about slab and have received some needed education from your response... Thanks for that Dave. So let me ask some questions instead of m

RE: [PATCH 7/8] zswap: add to mm/

2013-01-03 Thread Dan Magenheimer
> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > >> What I'm looking to do is give zswap a little insight into zsmalloc > >> internals, > > I'm putting at lot of thought into how to do it clea

Re: [PATCH 7/8] zswap: add to mm/

2013-01-03 Thread Seth Jennings
On 12/11/2012 03:56 PM, Seth Jennings wrote: > zswap is a thin compression backend for frontswap. It receives > pages from frontswap and attempts to store them in a compressed > memory pool, resulting in an effective partial memory reclaim and > dramatically reduced swap device I/O. > > Additional

Re: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Dave Chinner
On Wed, Jan 02, 2013 at 11:04:24AM -0800, Dan Magenheimer wrote: > > From: Dave Hansen [mailto:d...@linux.vnet.ibm.com] > > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > Hi Dave -- > > I suspect we are in violent agreement but just to make sure... > > Although z

Re: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Seth Jennings
On 01/02/2013 11:08 AM, Dan Magenheimer wrote: >> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] >> Subject: Re: [PATCH 7/8] zswap: add to mm/ >> >>> I am eagerly studying one of the details of your zswap "flush" >>> code in this patch to

Re: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Seth Jennings
On 01/02/2013 09:55 AM, Dave Hansen wrote: > On 01/01/2013 09:52 AM, Seth Jennings wrote: >> On 12/31/2012 05:06 PM, Dan Magenheimer wrote: >> Also, I've done some lockstat checks and the zswap tree lock is way >> down on the list contributing <1% of the lock contention wait time on >> a 4-core sys

RE: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Dan Magenheimer
> From: Dave Hansen [mailto:d...@linux.vnet.ibm.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ Hi Dave -- I suspect we are in violent agreement but just to make sure... Although zswap is the current example, I guess I am discussing a bigger issue, which IMHO is much more important

Re: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Dave Hansen
On 01/02/2013 09:26 AM, Dan Magenheimer wrote: > However if one compares the total percentage > of RAM used for zpages by zswap vs the total percentage of RAM > used by slab, I suspect that the zswap number will dominate, > perhaps because zswap is storing primarily data and slab is > storing prima

RE: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Dan Magenheimer
> From: Dave Hansen [mailto:d...@linux.vnet.ibm.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > On 01/01/2013 09:52 AM, Seth Jennings wrote: > > On 12/31/2012 05:06 PM, Dan Magenheimer wrote: > >> A second related issue that concerns me is that, although you

RE: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Dan Magenheimer
> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] > Subject: Re: [PATCH 7/8] zswap: add to mm/ > > > I am eagerly studying one of the details of your zswap "flush" > > code in this patch to see how you solved a problem or two that > > I was stru

Re: [PATCH 7/8] zswap: add to mm/

2013-01-02 Thread Dave Hansen
On 01/01/2013 09:52 AM, Seth Jennings wrote: > On 12/31/2012 05:06 PM, Dan Magenheimer wrote: >> A second related issue that concerns me is that, although you >> are now, like zcache2, using an LRU queue for compressed pages >> (aka "zpages"), there is no relationship between that queue and >> phys

Re: [PATCH 7/8] zswap: add to mm/

2013-01-01 Thread Seth Jennings
On 12/31/2012 05:06 PM, Dan Magenheimer wrote: >> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] >> Subject: [PATCH 7/8] zswap: add to mm/ >> >> zswap is a thin compression backend for frontswap. It receives >> pages from frontswap and attempts to store them in a compressed >> memory pool

RE: [PATCH 7/8] zswap: add to mm/

2012-12-31 Thread Dan Magenheimer
> From: Seth Jennings [mailto:sjenn...@linux.vnet.ibm.com] > Subject: [PATCH 7/8] zswap: add to mm/ > > zswap is a thin compression backend for frontswap. It receives > pages from frontswap and attempts to store them in a compressed > memory pool, resulting in an effective partial memory reclaim a