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* percpu, module: implement reserved allocation and use it for module percpu ↵Tejun Heo2009-03-061-20/+133
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | variables Impact: add reserved allocation functionality and use it for module percpu variables This patch implements reserved allocation from the first chunk. When setting up the first chunk, arch can ask to set aside certain number of bytes right after the core static area which is available only through a separate reserved allocator. This will be used primarily for module static percpu variables on architectures with limited relocation range to ensure that the module perpcu symbols are inside the relocatable range. If reserved area is requested, the first chunk becomes reserved and isn't available for regular allocation. If the first chunk also includes piggy-back dynamic allocation area, a separate chunk mapping the same region is created to serve dynamic allocation. The first one is called static first chunk and the second dynamic first chunk. Although they share the page map, their different area map initializations guarantee they serve disjoint areas according to their purposes. If arch doesn't setup reserved area, reserved allocation is handled like any other allocation. Signed-off-by: Tejun Heo <tj@kernel.org>
* percpu: add an indirection ptr for chunk page map accessTejun Heo2009-03-061-1/+4
| | | | | | | | | Impact: allow sharing page map, no functional difference yet Make chunk->page access indirect by adding a pointer and renaming the actual array to page_ar. This will be used by future changes. Signed-off-by: Tejun Heo <tj@kernel.org>
* percpu: use negative for auto for pcpu_setup_first_chunk() argumentsTejun Heo2009-03-061-21/+25
| | | | | | | | | | | | | | | 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: Tejun Heo <tj@kernel.org>
* percpu: improve first chunk initial area map handlingTejun Heo2009-03-061-26/+27
| | | | | | | | | | | | | | | | | | 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: Tejun Heo <tj@kernel.org>
* percpu: cosmetic renames in pcpu_setup_first_chunk()Tejun Heo2009-03-061-29/+29
| | | | | | | | | | | | | 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: Tejun Heo <tj@kernel.org>
* percpu: kill compile warning in pcpu_populate_chunk()Tejun Heo2009-03-011-1/+1
| | | | | | | | | | | | Impact: remove compile warning Mark local variable map_end in pcpu_populate_chunk() with uninitialized_var(). The variable is always used in tandem with map_start and guaranteed to be initialized before use but gcc doesn't understand that. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Ingo Molnar <mingo@elte.hu>
* percpu: add __read_mostly to variables which are mostly read onlyTejun Heo2009-02-241-8/+8
| | | | | | | | | Most global variables in percpu allocator are initialized during boot and read only from that point on. Add __read_mostly as per Rusty's suggestion. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
* percpu: give more latitude to arch specific first chunk initializationTejun Heo2009-02-241-33/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | Impact: more latitude for first percpu chunk allocation The first percpu chunk serves the kernel static percpu area and may or may not contain extra room for further dynamic allocation. Initialization of the first chunk needs to be done before normal memory allocation service is up, so it has its own init path - pcpu_setup_static(). It seems archs need more latitude while initializing the first chunk for example to take advantage of large page mapping. This patch makes the following changes to allow this. * Define PERCPU_DYNAMIC_RESERVE to give arch hint about how much space to reserve in the first chunk for further dynamic allocation. * Rename pcpu_setup_static() to pcpu_setup_first_chunk(). * Make pcpu_setup_first_chunk() much more flexible by fetching page pointer by callback and adding optional @unit_size, @free_size and @base_addr arguments which allow archs to selectively part of chunk initialization to their likings. Signed-off-by: Tejun Heo <tj@kernel.org>
* percpu: remove unit_size power-of-2 restrictionTejun Heo2009-02-241-14/+19
| | | | | | | | | | | | | Impact: allow unit_size to be arbitrary multiple of PAGE_SIZE In dynamic percpu allocator, there is no reason the unit size should be power of two. Remove the restriction. As non-power-of-two unit size means that empty chunks fall into the same slot index as lightly occupied chunks which is bad for reclaming. Reserve an extra slot for empty chunks. Signed-off-by: Tejun Heo <tj@kernel.org>
* vmalloc: add @align to vm_area_register_early()Tejun Heo2009-02-241-1/+1
| | | | | | | | | | | | Impact: allow larger alignment for early vmalloc area allocation Some early vmalloc users might want larger alignment, for example, for custom large page mapping. Add @align to vm_area_register_early(). While at it, drop docbook comment on non-existent @size. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
* percpu: fix pcpu_chunk_struct_sizeTejun Heo2009-02-241-1/+1
| | | | | | | | | | Impact: fix short allocation leading to memory corruption While dropping rvalue wrapping macros around global parameters, pcpu_chunk_struct_size was set incorrectly resulting in shorter page pointer array. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org>
* percpu: clean up size usageTejun Heo2009-02-211-11/+12
| | | | | | | | | | | | Andrew was concerned about the unit of variables named or have suffix size. Every usage in percpu allocator is in bytes but make it super clear by adding comments. While at it, make pcpu_depopulate_chunk() take int @off and @size like everyone else. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org>
* percpu: implement new dynamic percpu allocatorTejun Heo2009-02-201-0/+890
Impact: new scalable dynamic percpu allocator which allows dynamic percpu areas to be accessed the same way as static ones Implement scalable dynamic percpu allocator which can be used for both static and dynamic percpu areas. This will allow static and dynamic areas to share faster direct access methods. This feature is optional and enabled only when CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is defined by arch. Please read comment on top of mm/percpu.c for details. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org>
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