[PATCH 1/5] staging: zsmalloc: zsmalloc memory allocation library

Nitin Gupta ngupta at vflare.org
Mon Jan 23 18:57:36 UTC 2012

On 01/20/2012 05:12 PM, Andrew Morton wrote:

> On Mon,  9 Jan 2012 16:51:56 -0600
> Seth Jennings <sjenning at linux.vnet.ibm.com> wrote:
>> This patch creates a new memory allocation library named
>> zsmalloc.
> I haven't really begun to look at this yet.  The code is using many
> fields of struct page in new ways.  This is key information for anyone
> to effectively review the code.  So please carefully document (within
> the code itself) the ways in which the various page fields are used:
> semantic meaning of the overload, relationships between them, any
> locking rules or assumptions.  Ditto any other data structures.  This
> code should be reviewed very carefully by others so please implement it
> with that intention.

> It appears that a pile of dead code will be generated if CPU hotplug is
> disabled.  (That's if it compiles at all!).  Please take a look at users
> of hotcpu_notifier() - this facility cunningly causes all the hotplug code
> to vanish from vmlinux if it is unneeded.

ok, will look into these issues and add necessary documentation.

> afacit this code should be added to core mm/.  Addition of code like
> this to core mm/ will be fiercely resisted on principle!  Hence the
> (currently missing) justifications for adding it had best be good ones.

I don't think this code should ever get into mm/ since its just a driver
specific allocator. However its used by more than one driver (zcache and
zram) so it may be moved to lib/ or drivers/zsmalloc atmost?


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