2012/11/28 Joonsoo Kim <js1304@xxxxxxxxx>: > In current implementation, we used ARM-specific flag, that is, > VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area. > The purpose of static mapped area is to re-use static mapped area when > entire physical address range of the ioremap request can be covered > by this area. > > This implementation causes needless overhead for some cases. > For example, assume that there is only one static mapped area and > vmlist has 300 areas. Every time we call ioremap, we check 300 areas for > deciding whether it is matched or not. Moreover, even if there is > no static mapped area and vmlist has 300 areas, every time we call > ioremap, we check 300 areas in now. > > If we construct a extra list for static mapped area, we can eliminate > above mentioned overhead. > With a extra list, if there is one static mapped area, > we just check only one area and proceed next operation quickly. > > In fact, it is not a critical problem, because ioremap is not frequently > used. But reducing overhead is better idea. > > Another reason for doing this work is for removing architecture dependency > on vmalloc layer. I think that vmlist and vmlist_lock is internal data > structure for vmalloc layer. Some codes for debugging and stat inevitably > use vmlist and vmlist_lock. But it is preferable that they are used > as least as possible in outside of vmalloc.c > > Changelog > v1->v2: > [2/3]: patch description is improved. > Rebased on v3.7-rc7 > > Joonsoo Kim (3): > ARM: vmregion: remove vmregion code entirely > ARM: static_vm: introduce an infrastructure for static mapped area > ARM: mm: use static_vm for managing static mapped areas > > arch/arm/include/asm/mach/static_vm.h | 51 ++++++++ > arch/arm/mm/Makefile | 2 +- > arch/arm/mm/ioremap.c | 69 ++++------- > arch/arm/mm/mm.h | 10 -- > arch/arm/mm/mmu.c | 55 +++++---- > arch/arm/mm/static_vm.c | 97 ++++++++++++++++ > arch/arm/mm/vmregion.c | 205 --------------------------------- > arch/arm/mm/vmregion.h | 31 ----- > 8 files changed, 208 insertions(+), 312 deletions(-) > create mode 100644 arch/arm/include/asm/mach/static_vm.h > create mode 100644 arch/arm/mm/static_vm.c > delete mode 100644 arch/arm/mm/vmregion.c > delete mode 100644 arch/arm/mm/vmregion.h > > -- > 1.7.9.5 > Hello, Russell. Could you review this patchset, please? I send another patchset to mm community on top of this. That one is related to this patchset, so I want to get a review about this patchset :) Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>