diff options
author | Nicholas Piggin <npiggin@gmail.com> | 2017-06-09 01:36:09 +1000 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-06-15 16:34:39 +1000 |
commit | 07d2a628bc0008f90754ac7982289f6cb0f46cf8 (patch) | |
tree | fa8554770bf35735a791fd798a2dc3bd8ab45807 /drivers/watchdog/Kconfig | |
parent | 9145effd626d155484f73db24ab3e142ecda31db (diff) |
powerpc/64s: Avoid cpabort in context switch when possible
The ISA v3.0B copy-paste facility only requires cpabort when switching
to a process that has foreign real addresses mapped (direct access to
accelerators), to clear a potential copy buffer filled by a previous
thread. There is no accelerator driver implemented yet, so cpabort can
be removed. It can be be re-added when a driver is implemented.
POWER9 DD1 requires the copy buffer to always be cleared on context
switch, but if accelerators are not in use, then an unpaired copy from
a dummy region is sufficient to clear data out of the copy buffer.
This increases context switch performance by about 5% on POWER9.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/watchdog/Kconfig')
0 files changed, 0 insertions, 0 deletions