Messages in this thread | | | Date | Mon, 25 Oct 2021 22:42:33 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v4 0/2] fix & prevent the missing preemption disabling |
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On Tue, 26 Oct 2021 10:09:12 +0800 王贇 <yun.wang@linux.alibaba.com> wrote:
> Just a ping, to see if there are any more comments :-P
I guess you missed what went into mainline (and your name found a bug in my perl script for importing patches ;-)
https://lore.kernel.org/all/20211019091344.65629198@gandalf.local.home/
Which means patch 1 needs to change:
> + /* > + * Disable preemption to fulfill the promise. > + * > + * Don't worry about the bit 0 cases, they indicate > + * the disabling behaviour has already been done by > + * internal call previously. > + */ > + preempt_disable_notrace(); > + > return bit + 1; > } > > +/* > + * Preemption will be enabled (if it was previously enabled). > + */ > static __always_inline void trace_clear_recursion(int bit) > { > if (!bit) > return; > > + if (bit > 0) > + preempt_enable_notrace(); > +
Where this wont work anymore.
Need to preempt disable and enable always.
-- Steve
> barrier(); > bit--; > trace_recursion_clear(bit); > @@ -209,7 +227,7 @@ static __always_inline void trace_clear_recursion(int bit) > * tracing recursed in the same context (normal vs interrupt), > *
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