smp_rendezvous_action: Are atomics correctly used ?

[Alexandre Martins]

I have the save question for the cpu_ipi_pending here:

https://svnweb.freebsd.org/base/head/sys/x86/x86/mp_x86.c?view=annotate#l1080

Le jeudi 9 mars 2017, 10:43:14 Alexandre Martins a écrit :
> Hello,
> 
> I'm curently reading the code of the function smp_rendezvous_action, in
> kern/subr_smp.c file. In that function, i see that the variable
> smp_rv_waiters is read in some while() loop in a non-atomic way.
> 
> https://svnweb.freebsd.org/base/head/sys/kern/subr_smp.c?view=annotate#l412
> https://svnweb.freebsd.org/base/head/sys/kern/subr_smp.c?view=annotate#l458
> https://svnweb.freebsd.org/base/head/sys/kern/subr_smp.c?view=annotate#l472
> 
> I suspect one of my freeze to be due by that.
> 
> Should this function be patched to use
> "atomic_load_acq_int(&smp_rv_waiters[])" ?
> 
> Best regards

-- 
Alexandre Martins
STORMSHIELD

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