diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2017-09-21 16:52:44 +0100 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2017-09-27 17:09:57 +0200 |
| commit | e60aa7b53845a261dd419652f12ab9f89e668843 (patch) | |
| tree | 4fd8f76916b5ad7b393f6e9c1382cd36443ab4e5 /include/linux/iova.h | |
| parent | 086c83acb70fc6da044c9ca45c1c9780c64545b0 (diff) | |
iommu/iova: Extend rbtree node caching
The cached node mechanism provides a significant performance benefit for
allocations using a 32-bit DMA mask, but in the case of non-PCI devices
or where the 32-bit space is full, the loss of this benefit can be
significant - on large systems there can be many thousands of entries in
the tree, such that walking all the way down to find free space every
time becomes increasingly awful.
Maintain a similar cached node for the whole IOVA space as a superset of
the 32-bit space so that performance can remain much more consistent.
Inspired by work by Zhen Lei <thunder.leizhen@huawei.com>.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Zhen Lei <thunder.leizhen@huawei.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'include/linux/iova.h')
| -rw-r--r-- | include/linux/iova.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/iova.h b/include/linux/iova.h index d179b9bf7814..69ea3e258ff2 100644 --- a/include/linux/iova.h +++ b/include/linux/iova.h @@ -70,7 +70,8 @@ struct iova_fq { struct iova_domain { spinlock_t iova_rbtree_lock; /* Lock to protect update of rbtree */ struct rb_root rbroot; /* iova domain rbtree root */ - struct rb_node *cached32_node; /* Save last alloced node */ + struct rb_node *cached_node; /* Save last alloced node */ + struct rb_node *cached32_node; /* Save last 32-bit alloced node */ unsigned long granule; /* pfn granularity for this domain */ unsigned long start_pfn; /* Lower limit for this domain */ unsigned long dma_32bit_pfn; |