Messages in this thread | | | Date | Fri, 25 Jan 2013 11:26:17 -0800 | From | Greg KH <> | Subject | Re: [PATCH 2/2] staging: zcache: optional support for zsmalloc as alternate allocator |
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On Wed, Jan 23, 2013 at 01:46:31PM -0800, Dan Magenheimer wrote: > "New" zcache uses zbud for all sub-page allocation which is more flexible but > results in lower density. "Old" zcache supported zsmalloc for frontswap > pages. Add zsmalloc to "new" zcache as a compile-time and run-time option > for backwards compatibility in case any users wants to use zcache with > highest possible density. > > Note that most of the zsmalloc stats in old zcache are not included here > because old zcache used sysfs and new zcache has converted to debugfs. > These stats may be added later. > > Note also that ramster is incompatible with zsmalloc as the two use > the least significant bits in a pampd differently. > > Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> > --- > drivers/staging/zcache/Kconfig | 11 ++ > drivers/staging/zcache/zcache-main.c | 210 ++++++++++++++++++++++++++++++++-- > drivers/staging/zcache/zcache.h | 3 + > 3 files changed, 215 insertions(+), 9 deletions(-) > > diff --git a/drivers/staging/zcache/Kconfig b/drivers/staging/zcache/Kconfig > index c1dbd04..116f8d5 100644 > --- a/drivers/staging/zcache/Kconfig > +++ b/drivers/staging/zcache/Kconfig > @@ -10,6 +10,17 @@ config ZCACHE > memory to store clean page cache pages and swap in RAM, > providing a noticeable reduction in disk I/O. > > +config ZCACHE_ZSMALLOC > + bool "Allow use of zsmalloc allocator for compression of swap pages" > + depends on ZSMALLOC=y && !RAMSTER > + default n > + help > + Zsmalloc is a much more efficient allocator for compresssed > + pages but currently has some design deficiencies in that it > + does not support reclaim nor compaction. Select this if > + you are certain your workload will fit or has mostly short > + running processes. Zsmalloc is incompatible with RAMster.
How can anyone be "certain"?
> --- a/drivers/staging/zcache/zcache-main.c > +++ b/drivers/staging/zcache/zcache-main.c > @@ -26,6 +26,12 @@ > #include <linux/cleancache.h> > #include <linux/frontswap.h> > #include "tmem.h" > +#ifdef CONFIG_ZCACHE_ZSMALLOC > +#include "../zsmalloc/zsmalloc.h"
Don't #ifdef .h files in .c files.
> +static int zsmalloc_enabled; > +#else > +#define zsmalloc_enabled 0 > +#endif
That should have been your only ifdef in this .c file, all of the ones you have after this should not be needed, so I can't take this patch, sorry.
thanks,
greg k-h
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