Dear Matthew,
On 08/23/17 17:59, Matthew Tan wrote:
Calls to udelay are not preemtable by userspace so userspace
applications experience a large (~200us) latency when running on core
0. Instead usleep_range can be used to be more friendly to userspace
since it is preemtable. This is due to udelay using busy-wait loops
while usleep_rang uses hrtimers instead. It is recommended to use
udelay when the delay is <10us since at that precision overhead of
usleep_range hrtimer setup causes issues. However, the replaced calls
are for 50us and 100us so this should not be not an issue.
Is there a reason for indenting the paragraph. (I guess, you did `git
show` or `git log -p` and copied the message?) Anyway, please remove
whitespace in the front, if there is no reason.
Also, it looks like you ran benchmarks, so what is the delay for
userspace applications with your changes?
Signed-off-by: Matthew Tan <matthew.ta...@nxp.com>
---
drivers/net/ethernet/intel/e1000e/phy.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
[…]
Kind regards,
Paul
