Re: [Xen-devel] [PATCH v6 09/16 RESEND] rbtree: low level optimizations in __rb_erase_color()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 21.11.17 at 16:20, <kpraveen.lkml@xxxxxxxxx> wrote:
> From: Michel Lespinasse <walken@xxxxxxxxxx>
> 
> In __rb_erase_color(), we often already have pointers to the nodes being
> rotated and/or know what their colors must be, so we can generate more
> efficient code than the generic __rb_rotate_left() and __rb_rotate_right()
> functions.
> 
> Also when the current node is red or when flipping the sibling's color,
> the parent is already known so we can use the more efficient
> rb_set_parent_color() function to set the desired color.
> 
> Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> Acked-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
> Cc: Rik van Riel <riel@xxxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Daniel Santos <daniel.santos@xxxxxxxxx>
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> [Linux commit 6280d2356fd8ad0936a63c10dc1e6accf48d0c61]
> 
> Ported to Xen.
> 
> Signed-off-by: Praveen Kumar <kpraveen.lkml@xxxxxxxxx>

Acked-by: Jan Beulich <jbeulich@xxxxxxxx>



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel