Subject: [GIT PULL] x86, percpu: implement and use reserved percpu alloc
Newsgroups: gmane.linux.kernel
Date: 2009-03-06 06:46:20 GMT (3 years, 10 weeks, 1 day, 15 hours and 38 minutes ago)
Hello, Please pull from the following git vector. git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git tj-percpu This patchset implements reserved percpu alloc from the first chunk and uses it for static perpcu variables in modules on x86_64. This is necessary because x86_64 expects symbols to be relocatable using 32bit relocations but dynamic percpu allocation does not guarantee it leading to relocation overflow during module load. This can happen to any of the x86_64 percpu first chunk allocators but the embedding allocator is most likely to trigger it as the first chunk is located in the normal kernel memory allocation area while all the other chunks will be allocated in the vmalloc area which is very far from the first chunk. This type of reservation will be necessary for other architectures too where addressing mode used for percpu acess uses offsets with limited range to access symbols (e.g. ia64 w/ the magic 64k percpu page). This problem was first reported and bisected by Mike Galbraith[2]. This patchset is against the current x86/core/percpu[1] and contains the following patches. 0001-percpu-clean-up-percpu-constants.patch 0002-percpu-cosmetic-renames-in-pcpu_setup_first_chunk.patch 0003-percpu-improve-first-chunk-initial-area-map-handlin.patch 0004-percpu-use-negative-for-auto-for-pcpu_setup_first_c.patch 0005-x86-make-embedding-percpu-allocator-return-excessiv.patch 0006-percpu-add-an-indirection-ptr-for-chunk-page-map-ac.patch 0007-percpu-module-implement-reserved-allocation-and-us.patch 0008-x86-percpu-setup-reserved-percpu-area-for-x86_64.patch 0001-0004 makes misc updates to percpu in preparation of later changes. 0005 fixes a case where excessive memory can be set aside in the first chunk when using the embedding allocator. 0006-0008 implement reserved allocation and use it for x86_64. Bryan Wu, can you please review #0001? It contains small change in blackfin. It's mostly trivial but just in case. Diffstat follows. arch/blackfin/include/asm/percpu.h | 10 - arch/x86/kernel/setup_percpu.c | 73 +++++++--- include/linux/percpu.h | 60 +++----- kernel/module.c | 2 mm/percpu.c | 267 ++++++++++++++++++++++++++----------- 5 files changed, 274 insertions(+), 138 deletions(-) Thanks. -- tejun [1] f254f3909efaf59ca2d0f408de2d044dace60706 [2] http://thread.gmane.org/gmane.linux.kernel/801799