Messages in this thread | | | Date | Thu, 11 Dec 2008 09:46:12 +1000 | From | "Dave Airlie" <> | Subject | Re: [PATCH] lib/idr.c: Fix bug introduced by RCU fix |
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On Thu, Dec 11, 2008 at 3:17 AM, Manfred Spraul <manfred@colorfullife.com> wrote: > The last patch to lib/idr.c caused a bug if idr_get_new_above() was > called on an empty idr: > Usually, nodes stay on the same layer. New layers are added to the top > of the tree. > The exception is idr_get_new_above() on an empty tree: In this case, > the new root node is first added on layer 0, then moved upwards. > p->layer was not updated. > > As usual: You shall never rely on the source code comments, they > will only mislead you. > > Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
I've given this a run on my dri system and it appears to work great.
Tested-by: Dave Airlie <airlied@redhat.com>
> --- > lib/idr.c | 8 +++++++- > 1 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/lib/idr.c b/lib/idr.c > index 7a785a0..1c4f928 100644 > --- a/lib/idr.c > +++ b/lib/idr.c > @@ -220,8 +220,14 @@ build_up: > */ > while ((layers < (MAX_LEVEL - 1)) && (id >= (1 << (layers*IDR_BITS)))) { > layers++; > - if (!p->count) > + if (!p->count) { > + /* special case: if the tree is currently empty, > + * then we grow the tree by moving the top node > + * upwards. > + */ > + p->layer++; > continue; > + } > if (!(new = get_from_free_list(idp))) { > /* > * The allocation failed. If we built part of > -- > 1.5.6.5 > >
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