iommu/iova: Improve restart logic

Browse source

When restarting after searching below the cached node fails, resetting
the start point to the anchor node is often overly pessimistic. If
allocations are made with mixed limits - particularly in the case of the
opportunistic 32-bit allocation for PCI devices - this could mean
significant time wasted walking through the whole populated upper range
just to reach the initial limit. We can improve on that by implementing
a proper tree traversal to find the first node above the relevant limit,
and set the exact start point.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/076b3484d1e5057b95d8c387c894bd6ad2514043.1614962123.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

...

This commit is contained in:

Robin Murphy 2021-03-05 16:35:23 +00:00 • committed by Joerg Roedel

parent 7ae31cec5b

commit 371d7955e3

1 changed files with 38 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

39

drivers/iommu/iova.c

View file