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mirror: Don't count bytes transferred for the purposes of keeping the stream empty as part of our bwlimit

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This prevents a fairly nasty situation occurring where the rate of change on the disc is high enough that
just servicing it generates enough traffic to keep us over the bwlimit threshold indefinitely. That would
cause us to sleep during the only windows we'd ordinarily have to advance the offset.
This commit is contained in:
nick
2013-10-23 15:26:28 +01:00
parent 8cf9cae8c0
commit 335261869d
1 changed files with 9 additions and 2 deletions
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11
src/mirror.c
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@@ -357,7 +357,7 @@ int mirror_setup_next_xfer( struct mirror_ctrl *ctrl )
* full, and stop when it's a quarter full. This stops a busy client from * full, and stop when it's a quarter full. This stops a busy client from
* stalling a migration forever. FIXME: made-up numbers. * stalling a migration forever. FIXME: made-up numbers.
*/ */
if ( bitset_stream_size( serve->allocation_map ) > BITSET_STREAM_SIZE / 2 ) { if ( mirror->offset < serve->size && bitset_stream_size( serve->allocation_map ) > BITSET_STREAM_SIZE / 2 ) {
ctrl->clear_events = 1; ctrl->clear_events = 1;
} }
@@ -572,10 +572,17 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
/* transfer was completed, so now we need to either set up the next /* transfer was completed, so now we need to either set up the next
* transfer of this pass, set up the first transfer of the next pass, or * transfer of this pass, set up the first transfer of the next pass, or
* complete the migration */ * complete the migration */
m->all_dirty += xfer->len;
xfer->read = 0; xfer->read = 0;
xfer->written = 0; xfer->written = 0;
/* We don't account for bytes written in this mode, to stop high-throughput
* discs getting stuck in "drain the event queue!" mode forever
*/
if ( !ctrl->clear_events ) {
m->all_dirty += xfer->len;
}
/* This next bit could take a little while, which is fine */ /* This next bit could take a little while, which is fine */
ev_timer_stop( ctrl->ev_loop, &ctrl->timeout_watcher ); ev_timer_stop( ctrl->ev_loop, &ctrl->timeout_watcher );