Hi, This proposal extends xcall to allow to specify an IPL of the high priority xcall. Currently the high priority xcall uses only a softint of IPL_SOFTSERIAL. It doesn't work if the caller depends on a different softint IPL.
I'm now working on stability improvements of the network stack under load. psref_target_destroy can take longer time than we desire under load at worst, say 10 or 20 seconds. The cause of the delay is xcall and the delay can be mitigated by changing xcall to use the high priority. However it breaks atomicity of psref because psrefs used in the network stack normally run with IPL_SOFTNET. One workaround is to use IPL_SOFSERIAL for such psrefs but we should avoid using abnormal IPL as much as possible. So I propose the above enhancement to solve the issue. This is a patch implements the feature: http://www.netbsd.org/~ozaki-r/xcall-multi-ipl.diff The next patch applies it to psref: http://www.netbsd.org/~ozaki-r/xcall-multi-ipl-psref.diff The patch updates xcall.9 http://www.netbsd.org/~ozaki-r/xcall-multi-ipl-man.diff Any comments or suggestions? Thanks, ozaki-r
