On 15/03/2019 10:06, Dave Martin wrote:
On Thu, Mar 14, 2019 at 06:07:19PM +0000, Julien Grall wrote:
Hi Sebastian,
On 3/4/19 5:25 PM, Sebastian Andrzej Siewior wrote:
[...]
It would increase the softirq latency but the question is how bad would
it be. It would continue once the SIMD section is done.
On Arm, the kernel may use either FPSIMD or SVE (if supported by the
platform). While the FPSIMD context is fairly small (~4K), the SVE context
can be up to ~64KB.
It's not quite as bad as that. The FPSIMD state is ~0.5K, with the SVE
state size being up to ~8.5K (though for today's implementations ~2K may
be considered typical).
Whoops, I forgot to divide by 8. Thank you for spotting it!
Cheers,
--
Julien Grall
