On Fri, Mar 04, 2022 at 07:36:46AM +0800, Miles Chen wrote: > Hi Robin, > > > For various reasons based on the allocator behaviour and typical > > use-cases at the time, when the max32_alloc_size optimisation was > > introduced it seemed reasonable to couple the reset of the tracked > > size to the update of cached32_node upon freeing a relevant IOVA. > > However, since subsequent optimisations focused on helping genuine > > 32-bit devices make best use of even more limited address spaces, it > > is now a lot more likely for cached32_node to be anywhere in a "full" > > 32-bit address space, and as such more likely for space to become > > available from IOVAs below that node being freed. > > > > At this point, the short-cut in __cached_rbnode_delete_update() really > > doesn't hold up any more, and we need to fix the logic to reliably > > provide the expected behaviour. We still want cached32_node to only move > > upwards, but we should reset the allocation size if *any* 32-bit space > > has become available. > > > > Reported-by: Yunfei Wang <yf.wang@xxxxxxxxxxxx> > > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > > Would you mind adding: > > Cc: <stable@xxxxxxxxxxxxxxx> Applied without stable tag for now. If needed, please consider re-sending it for stable when this patch is merged upstream. Regards, Joerg
