Re: [PATCH v2 11/61] mm: Remove rb tree.

From: Liam Howlett
Date: Tue Aug 31 2021 - 10:40:46 EST


* David Hildenbrand <david@xxxxxxxxxx> [210823 05:49]:
> On 17.08.21 17:47, Liam Howlett wrote:
> > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> >
> > Remove the RB tree and start using the maple tree for vm_area_struct
> > tracking.
> >
> > Drop validate_mm() calls in expand_upwards() and expand_downwards() as
> > the lock is not held.
> >
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
>
>
> [...]
>
>
> Why are we reshuffling the code below? This either needs a good
> justification or should just be dropped as it introduces noise. Maybe I am
> missing something important.
>
> > /*
> > @@ -427,6 +414,11 @@ struct vm_area_struct {
> > pgprot_t vm_page_prot;
> > unsigned long vm_flags; /* Flags, see mm.h. */
> > + /* Information about our backing store: */
> > + unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
> > + * units
> > + */
> > + struct file *vm_file; /* File we map to (can be NULL). */
> > /*
> > * For areas with an address space and backing store,
> > * linkage into the address_space->i_mmap interval tree.
> > @@ -449,12 +441,9 @@ struct vm_area_struct {
> > /* Function pointers to deal with this struct. */
> > const struct vm_operations_struct *vm_ops;
> > - /* Information about our backing store: */
> > - unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
> > - units */
> > - struct file * vm_file; /* File we map to (can be NULL). */
> > void * vm_private_data; /* was vm_pte (shared mem) */
> > +

Thank you, I will drop this from the next revision.

>
> Another unrelated change (there seem to some more in this patch)

I'll have a look though it again.

Thanks,
Liam