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author | Balbir Singh <bsingharora@gmail.com> | 2018-04-06 15:24:23 +1000 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-04-24 09:46:56 +1000 |
commit | fb5924fddf9ee31db04da7ad4e8c3434a387101b (patch) | |
tree | be4e071f9cb1e80dd554d80f5667595e1879f3f4 /arch/.gitignore | |
parent | 6d08b06e67cd117f6992c46611dfb4ce267cd71e (diff) | |
download | linux-fb5924fddf9ee31db04da7ad4e8c3434a387101b.tar.bz2 |
powerpc/mm: Flush cache on memory hot(un)plug
This patch adds support for flushing potentially dirty cache lines
when memory is hot-plugged/hot-un-plugged. The support is currently
limited to 64 bit systems.
The bug was exposed when mappings for a device were actually
hot-unplugged and plugged in back later. A similar issue was observed
during the development of memtrace, but memtrace does it's own
flushing of region via a custom routine.
These patches do a flush both on hotplug/unplug to clear any stale
data in the cache w.r.t mappings, there is a small race window where a
clean cache line may be created again just prior to tearing down the
mapping.
The patches were tested by disabling the flush routines in memtrace
and doing I/O on the trace file. The system immediately
checkstops (quite reliablly if prior to the hot-unplug of the memtrace
region, we memset the regions we are about to hot unplug). After these
patches no custom flushing is needed in the memtrace code.
Fixes: 9d5171a8f248 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Reza Arbab <arbab@linux.ibm.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/.gitignore')
0 files changed, 0 insertions, 0 deletions