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Add new command to view the event queue

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Fixes to fake poll events to improve fairness
This commit is contained in:
Mark Riddoch 2014-10-17 08:36:32 +01:00
parent fe0e7c74d0
commit f459bdfe04
4 changed files with 59 additions and 7 deletions
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6
server/core/dcb.c
View File

@ -1389,6 +1389,12 @@ dprintDCB(DCB *pdcb, DCB *dcb)
dcb->stats.n_high_water);
dcb_printf(pdcb, "\t\tNo. of Low Water Events: %d\n",
dcb->stats.n_low_water);
if (DCB_POLL_BUSY(dcb))
{
dcb_printf(pdcb, "\t\tPending events in the queue: %x %s\n",
dcb->evq.pending_events, dcb->evq.processing ? "(processing)" : "");
}
if (dcb->flags & DCBF_CLONE)
dcb_printf(pdcb, "\t\tDCB is a clone.\n");
#if SPINLOCK_PROFILE

54
server/core/poll.c
View File

@ -1202,15 +1202,24 @@ poll_fake_write_event(DCB *dcb)
uint32_t ev = EPOLLOUT;
spinlock_acquire(&pollqlock);
/*
* If the DCB is already on the queue, there are no pending events and
* there are other events on the queue, then
* take it off the queue. This stops the DCB hogging the threads.
*/
if (DCB_POLL_BUSY(dcb) && dcb->evq.pending_events == 0 && dcb->evq.prev != dcb)
{
dcb->evq.prev->evq.next = dcb->evq.next;
dcb->evq.next->evq.prev = dcb->evq.prev;
if (eventq == dcb)
eventq = dcb->evq.next;
dcb->evq.next = NULL;
dcb->evq.prev = NULL;
pollStats.evq_length--;
}
if (DCB_POLL_BUSY(dcb))
{
if (dcb->evq.pending_events == 0)
{
pollStats.evq_pending++;
#if PROFILE_POLL
dcb->evq.inserted = hkheartbeat;
#endif
}
dcb->evq.pending_events |= ev;
}
else
@ -1241,3 +1250,34 @@ uint32_t ev = EPOLLOUT;
}
spinlock_release(&pollqlock);
}
/**
* Print the event queue contents
*
* @param pdcb The DCB to print the event queue to
*/
void
dShowEventQ(DCB *pdcb)
{
DCB *dcb;
int found = 0;
uint32_t ev;
spinlock_acquire(&pollqlock);
if (eventq == NULL)
{
/* Nothing to process */
spinlock_release(&pollqlock);
return 0;
}
dcb = eventq;
dcb_printf(pdcb, "%16s | %10s | %s\n", "DCB", "Status", "Events");
dcb_printf(pdcb, "-----------------+------------+--------------------\n");
do {
dcb_printf(pdcb, "%16p | %10s | %s\n", dcb,
dcb->evq.processing ? "Processing" : "Pending",
event_to_string(dcb->evq.pending_events));
dcb = dcb->evq.next;
} while (dcb != eventq);
spinlock_release(&pollqlock);
}

1
server/include/poll.h
View File

@ -42,4 +42,5 @@ extern void poll_shutdown();
extern GWBITMASK *poll_bitmask();
extern void dprintPollStats(DCB *);
extern void dShowThreads(DCB *dcb);
extern void dShowEventQ(DCB *dcb);
#endif

5
server/modules/routing/debugcmd.c
View File

@ -41,6 +41,7 @@
* than simply addresses
* 23/05/14 Mark Riddoch Added support for developer and user modes
* 29/05/14 Mark Riddoch Add Filter support
* 16/10/14 Mark Riddoch Add show eventq
*
* @endverbatim
*/
@ -116,6 +117,10 @@ struct subcommand showoptions[] = {
"Show the poll statistics",
"Show the poll statistics",
{0, 0, 0} },
{ "eventq", 0, dShowEventQ,
"Show the queue of events waiting to be processed",
"Show the queue of events waiting to be processed",
{0, 0, 0} },
{ "filter", 1, dprintFilter,
"Show details of a filter, called with a filter name",
"Show details of a filter, called with the address of a filter",