On Fri, May 27, 2011 at 12:49:25PM -0700, Dan Magenheimer wrote: > [PATCH V4 4/4] mm: frontswap: config and doc files > > Add configuration and documentation files. > > Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> > > Diffstat: > Documentation/ABI/testing/sysfs-kernel-mm-frontswap | 16 > Documentation/vm/frontswap.txt | 210 ++++++++++ > mm/Kconfig | 16 > mm/Makefile | 1 > 4 files changed, 243 insertions(+) > > --- linux-2.6.39/mm/Makefile 2011-05-18 22:06:34.000000000 -0600 > +++ linux-2.6.39-frontswap/mm/Makefile 2011-05-26 15:37:25.262292918 -0600 > @@ -25,6 +25,7 @@ obj-$(CONFIG_HAVE_MEMBLOCK) += memblock. > > obj-$(CONFIG_BOUNCE) += bounce.o > obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o > +obj-$(CONFIG_FRONTSWAP) += frontswap.o > obj-$(CONFIG_HAS_DMA) += dmapool.o > obj-$(CONFIG_HUGETLBFS) += hugetlb.o > obj-$(CONFIG_NUMA) += mempolicy.o > --- linux-2.6.39/mm/Kconfig 2011-05-18 22:06:34.000000000 -0600 > +++ linux-2.6.39-frontswap/mm/Kconfig 2011-05-26 15:39:26.294884780 -0600 > @@ -347,3 +347,19 @@ config NEED_PER_CPU_KM > depends on !SMP > bool > default y > + > +config FRONTSWAP > + bool "Enable frontswap pseudo-RAM driver to cache swap pages" > + default y default n > + help > + Frontswap is so named because it can be thought of as the opposite of > + a "backing" store for a swap device. The storage is assumed to be > + a synchronous concurrency-safe page-oriented pseudo-RAM device (such > + as Xen's Transcendent Memory, aka "tmem") which is not directly > + accessible or addressable by the kernel and is of unknown (and > + possibly time-varying) size. When a pseudo-RAM device is available, > + a signficant swap I/O reduction may be achieved. When none is > + available, all frontswap calls are reduced to a single pointer- > + compare-against-NULL resulting in a negligible performance hit. > + > + If unsure, say Y to enable frontswap. > --- linux-2.6.39/Documentation/ABI/testing/sysfs-kernel-mm-frontswap 1969-12-31 17:00:00.000000000 -0700 > +++ linux-2.6.39-frontswap/Documentation/ABI/testing/sysfs-kernel-mm-frontswap 2011-05-26 15:37:25.135819879 -0600 > @@ -0,0 +1,16 @@ > +What: /sys/kernel/mm/frontswap/ > +Date: June 2010 Not 2011? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>