cvs commit: src/share/man/man9 Makefile timeout.9 src/sys/sys callout.h src/sys/kern kern_timeout.c

Poul-Henning Kamp phk at
Sun Feb 6 22:33:27 PST 2005

In message <200502070247.j172lXIi069498 at>, Ian Dowse writes:
>iedowse     2005-02-07 02:47:33 UTC
>  FreeBSD src repository
>  Modified files:
>    share/man/man9       Makefile timeout.9 
>    sys/sys              callout.h 
>    sys/kern             kern_timeout.c 
>  Log:
>  Add a mechanism for associating a mutex with a callout when the
>  callout is first initialised, using a new function callout_init_mtx().
>  The callout system will acquire this mutex before calling the callout
>  function and release it on return.


But can we make softclock() use a two pass algorithm ?

First pass take all the timeouts which have a mutex which we can
get with mtx_lock_try() then in second pass all the rest of the
callouts for this tick ?

This would improve latency for well-written/locked code.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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