Messages in this thread |  | | | Date | Tue, 25 Jan 2011 18:31:11 +0100 | | From | Peter Zijlstra <> | | Subject | [PATCH 00/25] mm: Preemptibility -v7 |
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This patch-set makes part of the mm a lot more preemptible. It converts i_mmap_lock and anon_vma->lock to mutexes and makes mmu_gather fully preemptible.
The main motivation was making mm_take_all_locks() preemptible, since it appears people are nesting hundreds of spinlocks there.
The side-effects are that can finally make mmu_gather preemptible, something which lots of people have wanted to do for a long time.
It also gets us anon_vma refcounting, which seems to result in a nice cleanup of the anon_vma lifetime rules wrt KSM and compaction.
This patch-set is build and boot-tested on x86_64 (a previous version was also tested on Dave's Niagra2 machines, and I suppose s390 was too when Martin provided the conversion patch for his arch).
There are no known architectures left unconverted.
Yanmin ran the -v3 posting through the comprehensive Intel test farm and didn't find any regressions.
( Not included in this posting are the 4 Sparc64 patches that implement gup_fast, those can be applied separately after this series gets anywhere. )
The full series (including the Sparc64 gup_fast bits) also available in -git form from (against something post .38-rc2):
git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-mmu_preempt.git
Changes since -v6:
Suggested by Hugh: - reordered the patches - changed to GFP_NOWAIT | __GFP_NOWARN to allocate mmu_gather pages - s/lock/mutex/ for the spinlock to mutex conversion - removed all DEFINE_PER_CPU(struct mmu_gather, mmu_gather) remnants - split the i_mmap_lock and anon_vma->lock conversion - removed some KSM wrappers - avoid tlb_flush_mmu() while holding pte_lock Other: - remove the i_mmap_lock lockbreak in truncate (XXX) - arch/tile __pte_free_tlb() change
TODO: - decide if we want to actually remove the i_mmap_lock lockbreak - figure out if LOCK vs MB works or add a smp_mb() to patch #23 - figure out what to do with sparc's tlb_batch lack of ->fullmm
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