The patch collapses in the internal zsmalloc_int.h into
the zsmalloc-main.c file.
This is done in preparation for the promotion to mm/ where
separate internal headers are discouraged.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patchset provides page mapping via the page table.
On some archs, most notably ARM, this method has been
demonstrated to be faster than copying.
The logic controlling the method selection (copy vs page table)
is controlled by the definition of USE_PGTABLE_MAPPING which
is/can be defined for any arch that performs better with page
table mapping.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because we use per-cpu mapping areas shared among the
pools/users, we can't allow mapping in interrupt context
because it can corrupt another users mappings.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
firstpage already has precedent and meaning the first page
of a zspage. In the case of the copy mapping functions,
it is the first of a pair of pages needing to be mapped.
This patch just renames the firstpage argument to "page" to
avoid confusion.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch improves mapping performance in zsmalloc by getting
usage information from the user in the form of a "mapping mode"
and using it to avoid unnecessary copying for objects that span
pages.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add information on the usage limits of zs_map_object()
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Improve zs_unmap_object() performance by adding a fast path for
objects that don't span pages.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces the page table assisted object mapping
method, which has x86 dependencies, with a arch-independent
method that does a simple copy into a temporary per-cpu
buffer.
While a copy seems like it would be worse than mapping the pages,
tests demonstrate the copying is always faster and, in the case of
running inside a KVM guest, roughly 4x faster.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ZSMALLOC is tristate, but the code has no MODULE_LICENSE and since it
depends on GPL-only symbols it cannot be loaded as a module. This in
turn breaks zram which now depends on it. I assume it's meant to be
Dual BSD/GPL like the other z-stuff.
There is also no module_exit, which will make it impossible to unload.
Add the appropriate module_init and module_exit declarations suggested
by comments.
Reported-by: Christian Ohm <chr.ohm@gmx.net>
References: http://bugs.debian.org/677273
Cc: stable@vger.kernel.org # v3.4
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes an uninitialized variable warning in
alloc_zspage(). It also fixes the secondary issue of
prev_page leaving scope on each loop iteration. The only
reason this ever worked was because prev_page was occupying
the same space on the stack on each iteration.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation of various struct page fields
used by zsmalloc.
Changes for v2:
- Regroup descriptions as suggested by Konrad
Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should use unsigned long as handle instead of void * to avoid any
confusion. Without this, users may just treat zs_malloc return value as
a pointer and try to deference it.
This patch passed compile test(zram, zcache and ramster) and zram is
tested on qemu.
changelog
* from v2
- remove hval pointed out by Nitin
- based on next-20120607
* from v1
- change zcache's zv_create return value
- baesd on next-20120604
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
zspage_order defines how many pages are needed to make a zspage.
So _order_ is rather awkward naming. It already deceive Jonathan
- http://lwn.net/Articles/477067/
" For each size, the code calculates an optimum number of pages (up to 16)"
Let's change from _order_ to _pages_ and some function names.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a memory leak in zsmalloc where the first
subpage of each zspage is leaked when the zspage is freed.
Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch ensures that the value of ZS_MIN_ALLOC_SIZE, for the
PAGE_SIZE and MAX_PHYSMEM_BITS on the system, allows for all
possible object ids in the lowest storage class to be encoded
in the object handle.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch provides a way to determine or "set a
reasonable value for" MAX_PHYSMEM_BITS in the case that
it is not defined (i.e. !SPARSEMEM)
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch moves where max_zspage_order is declared and
changes its meaning. "Order" typically implies 2^order
of something; however, it is currently being used as the
"maximum number of single pages in a zspage". To add clarity,
ZS_MAX_ZSPAGE_ORDER is now used to calculate ZS_MAX_PAGES_PER_ZSPAGE,
which is 2^ZS_MAX_ZSPAGE_ORDER and is the upper bound on the number
of pages in a zspage.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch moves the definitions of _PFN_BITS, OBJ_INDEX_BITS
and OBJ_INDEX_MASK from zsmalloc-main.c to zsmalloc_int.h
They will be needed to determine ZS_MIN_ALLOC_SIZE in the next
patch
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
linux/vmalloc.h added to zsmalloc-main.c to resolve implicit
declaration errors.
X86 dependency added to zsmalloc and dependent drivers zcache and zram.
This X86 only requirement is not ideal. Working to find portable
functions for __flush_tlb_one and set_pte.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch creates a new memory allocation library named
zsmalloc.
NOTE: zsmalloc currently depends on SPARSEMEM for the MAX_PHYSMEM_BITS
value needed to determine the format of the object handle. There may
be a better way to do this. Feedback is welcome.
Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Seth Jennings