Messages in this thread | | | Date | Fri, 27 Sep 2013 13:46:37 -0700 | From | Cody P Schafer <> | Subject | Re: [PATCHv4 02/10] mm: convert mm->nr_ptes to atomic_t |
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On 09/27/2013 06:16 AM, Kirill A. Shutemov wrote: > With split page table lock for PMD level we can't hold > mm->page_table_lock while updating nr_ptes. > > Let's convert it to atomic_t to avoid races. >
> ---
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 84e0c56e1e..99f19e850d 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -339,6 +339,7 @@ struct mm_struct { > pgd_t * pgd; > atomic_t mm_users; /* How many users with user space? */ > atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ > + atomic_t nr_ptes; /* Page table pages */ > int map_count; /* number of VMAs */ > > spinlock_t page_table_lock; /* Protects page tables and some counters */ > @@ -360,7 +361,6 @@ struct mm_struct { > unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */ > unsigned long stack_vm; /* VM_GROWSUP/DOWN */ > unsigned long def_flags; > - unsigned long nr_ptes; /* Page table pages */ > unsigned long start_code, end_code, start_data, end_data; > unsigned long start_brk, brk, start_stack; > unsigned long arg_start, arg_end, env_start, env_end;
Will 32bits always be enough here? Should atomic_long_t be used instead?
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