Messages in this thread | | | Date | Thu, 01 Apr 2010 14:17:32 +0300 | From | Avi Kivity <> | Subject | Re: [COUNTERPATCH] mm: avoid overflowing preempt_count() in mmu_take_all_locks() |
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On 04/01/2010 02:13 PM, Avi Kivity wrote: > >> Anyway, I don't see a reason why we can't convert those locks to >> mutexes and get rid of the whole preempt disabled region. > > If someone is willing to audit all code paths to make sure these locks > are always taken in schedulable context I agree that's a better fix. >
From mm/rmap.c:
> /* > * Lock ordering in mm: > * > * inode->i_mutex (while writing or truncating, not reading or > faulting) > * inode->i_alloc_sem (vmtruncate_range) > * mm->mmap_sem > * page->flags PG_locked (lock_page) > * mapping->i_mmap_lock > * anon_vma->lock ... > * > * (code doesn't rely on that order so it could be switched around) > * ->tasklist_lock > * anon_vma->lock (memory_failure, collect_procs_anon) > * pte map lock > */
i_mmap_lock is a spinlock, and tasklist_lock is a rwlock, so some changes will be needed.
-- error compiling committee.c: too many arguments to function
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