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  1. Mar 06, 2009
    • Tejun Heo's avatar
      x86: make embedding percpu allocator return excessive free space · 9a4f8a87
      Tejun Heo authored 
      

Impact: reduce unnecessary memory usage on certain configurations

Embedding percpu allocator allocates unit_size *
smp_num_possible_cpus() bytes consecutively and use it for the first
chunk.  However, if the static area is small, this can result in
excessive prellocated free space in the first chunk due to
PCPU_MIN_UNIT_SIZE restriction.

This patch makes embedding percpu allocator preallocate only what's
necessary as described by PERPCU_DYNAMIC_RESERVE and return the
leftover to the bootmem allocator.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      9a4f8a87
    • Tejun Heo's avatar
      percpu: use negative for auto for pcpu_setup_first_chunk() arguments · cafe8816
      Tejun Heo authored 
      

Impact: argument semantic cleanup

In pcpu_setup_first_chunk(), zero @unit_size and @dyn_size meant
auto-sizing.  It's okay for @unit_size as 0 doesn't make sense but 0
dynamic reserve size is valid.  Alos, if arch @dyn_size is calculated
from other parameters, it might end up passing in 0 @dyn_size and
malfunction when the size is automatically adjusted.

This patch makes both @unit_size and @dyn_size ssize_t and use -1 for
auto sizing.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      cafe8816
    • Tejun Heo's avatar
      percpu: improve first chunk initial area map handling · 61ace7fa
      Tejun Heo authored 
      

Impact: no functional change

When the first chunk is created, its initial area map is not allocated
because kmalloc isn't online yet.  The map is allocated and
initialized on the first allocation request on the chunk.  This works
fine but the scattering of initialization logic between the init
function and allocation path is a bit confusing.

This patch makes the first chunk initialize and use minimal statically
allocated map from pcpu_setpu_first_chunk().  The map resizing path
still needs to handle this specially but it's more straight-forward
and gives more latitude to the init path.  This will ease future
changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      61ace7fa
    • Tejun Heo's avatar
      percpu: cosmetic renames in pcpu_setup_first_chunk() · 2441d15c
      Tejun Heo authored 
      

Impact: cosmetic, preparation for future changes

Make the following renames in pcpur_setup_first_chunk() in preparation
for future changes.

* s/free_size/dyn_size/
* s/static_vm/first_vm/
* s/static_chunk/schunk/

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      2441d15c
    • Tejun Heo's avatar
      percpu: clean up percpu constants · 6a242909
      Tejun Heo authored 
      

Impact: cleaup

Make the following cleanups.

* There isn't much arch-specific about PERCPU_MODULE_RESERVE.  Always
  define it whether arch overrides PERCPU_ENOUGH_ROOM or not.

* blackfin overrides PERCPU_ENOUGH_ROOM to align static area size.  Do
  it by default.

* percpu allocation sizes doesn't have much to do with the page size.
  Don't use PAGE_SHIFT in their definition.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Bryan Wu <cooloney@kernel.org>
      6a242909
  3. Mar 04, 2009
  5. Mar 03, 2009
  7. Mar 02, 2009
    • Jeremy Fitzhardinge's avatar
      xen: deal with virtually mapped percpu data · 9976b39b
      Jeremy Fitzhardinge authored 
      

The virtually mapped percpu space causes us two problems:

 - for hypercalls which take an mfn, we need to do a full pagetable
   walk to convert the percpu va into an mfn, and

 - when a hypercall requires a page to be mapped RO via all its aliases,
   we need to make sure its RO in both the percpu mapping and in the
   linear mapping

This primarily affects the gdt and the vcpu info structure.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      9976b39b