On 6/16/26 3:17 PM, Michael S. Tsirkin wrote:
On Tue, Jun 16, 2026 at 02:55:52PM +1000, Gavin Shan wrote:
On 6/16/26 2:49 PM, Michael S. Tsirkin wrote:
On Mon, Jun 15, 2026 at 09:48:00PM -0700, Richard Henderson wrote:
On 6/15/26 21:23, Michael S. Tsirkin wrote:
B. Also on x86, I do not see why we should not use memcpy for large
accesses if we can. Better perf.
We have an example where memcpy writes to the same location 3 times.
This is not appropriate for any host.
r~
as in, same byte? could you share the details pls?
This issue happened on aarch64 only.
https://lore.kernel.org/qemu-devel/cafeaca8dwhv8f48kb-013rxkg9kkczhym9_qarkmoeufeh0...@mail.gmail.com/
Thanks,
Gavin
oh wow. thanks for sharing!
Still I think for sizes outside of 2,4,8 it's fine?
That is where the perf is.
For that point, I agree with you that it's fine to use memcpy/memmove
when the length is 16-bytes or more, unless Richard is concerned by
this.
I'm posting (v3) and lets continue the discussion on (v3) series. Sorry
for taking your guys so many time to review and discuss ;-)
Thanks,
Gavin
