This patchset removes vm_struct list management after initializing
vmalloc. Adding and removing an entry to vmlist is linear time
complexity, so it is inefficient. If we maintain this list, overall
time complexity of adding and removing area to vmalloc space is O(N),
although we use rbtree for finding vacant place and it's time complexity
is just O(logN).
And vmlist and vmlist_lock is used many places of outside of vmalloc.c.
It is preferable that we hide this raw data structure and provide
well-defined function for supporting them, because it makes that they
cannot mistake when manipulating theses structure and it makes us easily
maintain vmalloc layer.
For kexec and makedumpfile, I export vmap_area_list, instead of vmlist.
This comes from Atsushi's recommendation. For more information, please
refer below link. https://lkml.org/lkml/2012/12/6/184
This patch:
The purpose of iterating a vmlist is finding vm area with specific virtual
address. find_vm_area() is provided for this purpose and more efficient,
because it uses a rbtree. So change it.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
swap_lock is heavily contended when I test swap to 3 fast SSD (even
slightly slower than swap to 2 such SSD). The main contention comes
from swap_info_get(). This patch tries to fix the gap with adding a new
per-partition lock.
Global data like nr_swapfiles, total_swap_pages, least_priority and
swap_list are still protected by swap_lock.
nr_swap_pages is an atomic now, it can be changed without swap_lock. In
theory, it's possible get_swap_page() finds no swap pages but actually
there are free swap pages. But sounds not a big problem.
Accessing partition specific data (like scan_swap_map and so on) is only
protected by swap_info_struct.lock.
Changing swap_info_struct.flags need hold swap_lock and
swap_info_struct.lock, because scan_scan_map() will check it. read the
flags is ok with either the locks hold.
If both swap_lock and swap_info_struct.lock must be hold, we always hold
the former first to avoid deadlock.
swap_entry_free() can change swap_list. To delete that code, we add a
new highest_priority_index. Whenever get_swap_page() is called, we
check it. If it's valid, we use it.
It's a pity get_swap_page() still holds swap_lock(). But in practice,
swap_lock() isn't heavily contended in my test with this patch (or I can
say there are other much more heavier bottlenecks like TLB flush). And
BTW, looks get_swap_page() doesn't really need the lock. We never free
swap_info[] and we check SWAP_WRITEOK flag. The only risk without the
lock is we could swapout to some low priority swap, but we can quickly
recover after several rounds of swap, so sounds not a big deal to me.
But I'd prefer to fix this if it's a real problem.
"swap: make each swap partition have one address_space" improved the
swapout speed from 1.7G/s to 2G/s. This patch further improves the
speed to 2.3G/s, so around 15% improvement. It's a multi-process test,
so TLB flush isn't the biggest bottleneck before the patches.
[arnd@arndb.de: fix it for nommu]
[hughd@google.com: add missing unlock]
[minchan@kernel.org: get rid of lockdep whinge on sys_swapon]
Signed-off-by: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This change implements PCIe root complex support for tilegx using
the kernel support layer for accessing the TRIO hardware shim.
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> [changes in 07487f3]
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change adds support for a new "super" bit in the PTE, using the new
arch_make_huge_pte() method. The Tilera hypervisor sees the bit set at a
given level of the page table and gangs together 4, 16, or 64 consecutive
pages from that level of the hierarchy to create a larger TLB entry.
One extra "super" page size can be specified at each of the three levels
of the page table hierarchy on tilegx, using the "hugepagesz" argument
on the boot command line. A new hypervisor API is added to allow Linux
to tell the hypervisor how many PTEs to gang together at each level of
the page table.
To allow pre-allocating huge pages larger than the buddy allocator can
handle, this change modifies the Tilera bootmem support to put all of
memory on tilegx platforms into bootmem.
As part of this change I eliminate the vestigial CONFIG_HIGHPTE support,
which never worked anyway, and eliminate the hv_page_size() API in favor
of the standard vma_kernel_pagesize() API.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change introduces new flags for the hv_install_context()
API that passes a page table pointer to the hypervisor. Clients
can explicitly request 4K, 16K, or 64K small pages when they
install a new context. In practice, the page size is fixed at
kernel compile time and the same size is always requested every
time a new page table is installed.
The <hv/hypervisor.h> header changes so that it provides more abstract
macros for managing "page" things like PFNs and page tables. For
example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old
HV_PAGE_SIZE_SMALL. The various PFN routines have been eliminated and
only PA- or PTFN-based ones remain (since PTFNs are always expressed
in fixed 2KB "page" size). The page-table management macros are
renamed with a leading underscore and take page-size arguments with
the presumption that clients will use those macros in some single
place to provide the "real" macros they will use themselves.
I happened to notice the old hv_set_caching() API was totally broken
(it assumed 4KB pages) so I changed it so it would nominally work
correctly with other page sizes.
Tag modules with the page size so you can't load a module built with
a conflicting page size. (And add a test for SMP while we're at it.)
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We should be holding the init_mm.page_table_lock in shatter_huge_page()
since we are modifying the kernel page tables. Then, only if we are
walking the other root page tables to update them, do we want to take
the pgd_lock.
Add a comment about taking the pgd_lock that we always do it with
interrupts disabled and therefore are not at risk from the tlbflush
IPI deadlock as is seen on x86.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We make sure not to try to set the home for an MMIO PTE (on tilegx)
or a PTE that isn't referencing memory managed by Linux.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Commit ddd588b5dd ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():
lib/lib.a(show_mem.o): In function `show_mem':
show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
arch/sparc/mm/built-in.o:(.text+0xd70): first defined here
The fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.
Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Tilera architecture traditionally supports 64KB page sizes
to improve TLB utilization and improve performance when the
hardware is being used primarily to run a single application.
For more generic server scenarios, it can be beneficial to run
with 4KB page sizes, so this commit allows that to be specified
(by modifying the arch/tile/include/hv/pagesize.h header).
As part of this change, we also re-worked the PTE management
slightly so that PTE writes all go through a __set_pte() function
where we can do some additional validation. The set_pte_order()
function was eliminated since the "order" argument wasn't being used.
One bug uncovered was in the PCI DMA code, which wasn't properly
flushing the specified range. This was benign with 64KB pages,
but with 4KB pages we were getting some larger flushes wrong.
The per-cpu memory reservation code also needed updating to
conform with the newer percpu stuff; before it always chose 64KB,
and that was always correct, but with 4KB granularity we now have
to pay closer attention and reserve the amount of memory that will
be requested when the percpu code starts allocating.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Tile's __pte_free_tlb() implementation makes assumptions about the
generic mmu_gather implementation, cure this ;-)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change makes KM_TYPE_NR independent of the actual deprecated
list of km_type values, which are no longer used in tile code anywhere.
For now we leave it set to 8, allowing that many nested mappings,
and thus reserving 32MB of address space.
A few remaining places using KM_* values were cleaned up as well.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is primarily changes caused by reviewing "sparse"
and "checkpatch" output on our sources, so is somewhat noisy, since
things like "printk() -> pr_err()" (or whatever) throughout the
codebase tend to get tedious to read. Rather than trying to tease
apart precisely which things changed due to which type of code
review, this commit includes various cleanups in the code:
- sparse: Add declarations in headers for globals.
- sparse: Fix __user annotations.
- sparse: Using gfp_t consistently instead of int.
- sparse: removing functions not actually used.
- checkpatch: Clean up printk() warnings by using pr_info(), etc.;
also avoid partial-line printks except in bootup code.
- checkpatch: Use exposed structs rather than typedefs.
- checkpatch: Change some C99 comments to C89 comments.
In addition, a couple of minor other changes are rolled in
to this commit:
- Add support for a "raise" instruction to cause SIGFPE, etc., to be raised.
- Remove some compat code that is unnecessary when we fully eliminate
some of the deprecated syscalls from the generic syscall ABI.
- Update the tile_defconfig to reflect current config contents.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.
This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>
