I misunderstood the UTRACE_INTERRUPT without UTRACE_EVENT(QUIESCE) above
as if you mean it is possible to get UTRACE_SIGNAL_REPORT without QUIESCE.
No, I meant the opposite: since you won't get UTRACE_SIGNAL_REPORT without
UTRACE_EVENT(QUIESCE), it might seem that UTRACE_INTERRUPT should not be
On 09/03, Roland McGrath wrote:
So, it is technically kosher enough to use UTRACE_INTERRUPT without
UTRACE_EVENT(QUIESCE) set, if you really know the situation and are sure
about all those caveats above.
How? see below.
I mentioned the examples.
I misunderstood the
Hmm. I am not sure I understand. If -report_signal != NULL, then
you can't expect -report_quiesce() after utrace_control(INTERRUPT) ?
Sorry, I used report_quiesce as shorthand for either report_quiesce, or
report_signal with UTRACE_SIGNAL_REPORT.
So, it is technically kosher enough to use
But probably we need utrace_detached_ops-report_reap() anyway.
-report_death can return UTRACE_DETACH, and after that utrace_report_death()
can skip utrace_reset() and do -report_reap().
Yeah, that's a good point. There's no good reason to do a special case
check for detached_ops there rather
I was going to ping you ;) This is connected to the problem I hit today.
Despite the fact I already complained about utrace_get_signal() QUIESCE,
I forgot about this and figured out it doesn't work in practice.
On 09/02, Roland McGrath wrote:
If an engine used UTRACE_INTERRUPT without having
On 08/19, Roland McGrath wrote:
OK, instead of filling utrace_detached_ops{} we can change start_callback()
- if (want UTRACE_EVENT(QUIESCE)) {
+ if ((want UTRACE_EVENT(QUIESCE)) || ops == detached_ops) {
If we're going to have a special-case check for utrace_detached_ops,
On 08/17, Oleg Nesterov wrote:
Suppose that, say, engine-flags == UTRACE_EVENT(EXEC) (no QUIESCE).
1. start_callback() reads want = engine-flags (== EXEC)
2. mark_engine_detached() sets engine-ops = utrace_detached_ops
3. start_callback() gets ops = utrace_detached_ops
On 08/16, Oleg Nesterov wrote:
Well, I tried to test these changes, seems to work.
But... From 2/3 changelog:
This means that
mark_engine_detached() can race with REPORT_CALLBACKS() but there
is nothing new.
Yes, there is nothing new. But, Roland, this is WRONG!
With
Whatever we do, start_callback() can see the old engine-flags but
the new -ops = utrace_detached_ops. Just suppose that the caller
of UTRACE_DETACH is interrupted right after setting engine-ops.
* it can check the old flags before using the old ops, or check the old
* flags before using the
