lkml.org 
[lkml]   [2005]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Real-Time Preemption and RCU
    On Tue, 22 Mar 2005, Ingo Molnar wrote:

    >
    > * Esben Nielsen <simlo@phys.au.dk> wrote:
    >
    > > +static inline void rcu_read_lock(void)
    > > +{
    > > + preempt_disable();
    > > + __get_cpu_var(rcu_data).active_readers++;
    > > + preempt_enable();
    > > +}
    >
    > this is buggy. Nothing guarantees that we'll do the rcu_read_unlock() on
    > the same CPU, and hence ->active_readers can get out of sync.
    >

    Ok, this have to be handled in the mitigration code somehow. I have already
    added an
    current->rcu_read_depth++
    so it ought to be painless. A simple solution would be not to mititagrate
    threads with rcu_read_depth!=0.

    > Ingo
    >

    Esben

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-04-06 13:30    [W:8.297 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site