Messages in this thread |  | | | Date | Fri, 25 Sep 2009 17:40:09 +0900 | | From | KAMEZAWA Hiroyuki <> | | Subject | Re: No more bits in vm_area_struct's vm_flags. |
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On Fri, 25 Sep 2009 18:34:56 +1000 Nigel Cunningham <ncunningham@crca.org.au> wrote:
> Hi. > > KAMEZAWA Hiroyuki wrote: > >> I have some code in TuxOnIce that needs a bit too (explicitly mark the > >> VMA as needing to be atomically copied, for GEM objects), and am not > >> sure what the canonical way to proceed is. Should a new unsigned long be > >> added? The difficulty I see with that is that my flag was used in > >> shmem_file_setup's flags parameter (drm_gem_object_alloc), so that > >> function would need an extra parameter too.. > > > > Hmm, how about adding vma->vm_flags2 ? > > The difficulty there is that some functions pass these flags as arguments. > Ah yes. But I wonder some special flags, which is rarey used, can be moved to vm_flags2...
For example,
#define VM_SEQ_READ 0x00008000 /* App will access data sequentially */ #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */ are all capsuled under mm.h 117 #define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ) 118 #define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK 119 #define VM_NormalReadHint(v) (!((v)->vm_flags & VM_READHINTMASK)) 120 #define VM_SequentialReadHint(v) ((v)->vm_flags & VM_SEQ_READ) 121 #define VM_RandomReadHint(v) ((v)->vm_flags & VM_RAND_READ) Or
105 #define VM_PFN_AT_MMAP 0x40000000 /* PFNMAP vma that is fully mapped at mmap time */ is only used under special situation. etc..
They'll be able to be moved to other(new) flag field, IIUC.
Thanks, -Kame
> Regards, > > Nigel > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >
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