linux/tools
Matthew Wilcox 070c5ac274 radix-tree: fix radix_tree_range_tag_if_tagged() for multiorder entries
I had previously decided that tagging a single multiorder entry would
count as tagging 2^order entries for the purposes of 'nr_to_tag'.  I now
believe that decision to be a mistake, and it should count as a single
entry.  That's more likely to be what callers expect.

When walking back up the tree from a newly-tagged entry, the current
code assumed we were starting from the lowest level of the tree; if we
have a multiorder entry with an order at least RADIX_TREE_MAP_SHIFT in
size then we need to shift the index by 'shift' before we start walking
back up the tree, or we will end up not setting tags on higher entries,
and then mistakenly thinking that entries below a certain point in the
tree are not tagged.

If the first index we examine is a sibling entry of a tagged multiorder
entry, we were not tagging it.  We need to examine the canonical entry,
and the easiest way to do that is to use radix_tree_descend().  We then
have to skip over sibling slots when looking for the next entry in the
tree or we will end up walking back to the canonical entry.

Add several tests for radix_tree_range_tag_if_tagged().

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
..
arch
build perf probe: Check if dwarf_getlocations() is available 2016-05-12 11:26:59 -03:00
cgroup
firewire
gpio tools/gpio: Add missing initialization of device_name 2016-03-31 11:51:30 +02:00
hv tools/hv: Use include/uapi with __EXPORTED_HEADERS__ 2016-02-07 21:34:12 -08:00
iio
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-24 10:02:14 -07:00
laptop/freefall
lguest tools/lguest: Force disable tboot and APM 2016-04-22 10:29:03 +02:00
lib Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-16 14:08:43 -07:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd
objtool objtool: Detect falling through to the next function 2016-04-16 11:14:17 +02:00
perf powerpc updates for 4.7 2016-05-20 10:12:41 -07:00
power ACPI material for v4.7-rc1 2016-05-16 19:41:41 -07:00
scripts tools: Move utilities.mak from perf to tools/scripts/ 2016-03-18 13:57:20 -03:00
spi
testing radix-tree: fix radix_tree_range_tag_if_tagged() for multiorder entries 2016-05-20 17:58:30 -07:00
thermal/tmon
time
usb
virtio virtio_ring: Support DMA APIs 2016-03-02 17:01:57 +02:00
vm tools/vm/page-types.c: avoid memset() in walk_pfn() when count == 1 2016-03-17 15:09:34 -07:00
Makefile tools build: Fix perf_clean target 2016-04-25 17:59:36 -03:00