mirror of https://gitee.com/openkylin/linux.git
e4d7d6f4d3
When batching more updates to the activity log into single transactions, we lost the ability for new requests to force themselves into the active set: all preparation steps became non-blocking, and if all currently hot extents keep busy, they could starve out new incoming requests to cold extents for quite a while. This can only happen if your IO backend accepts more IO operations per average DRBD replication round trip time than you have al-extents configured. If we have incoming requests to cold extents, at least do one blocking update per transaction. In an artificial worst-case workload on SSD with an asynchronous 600 ms replication link, with al-extents = 7 (the minimum we allow), and concurrent full resynch, without this patch, some write requests have been observed to be starved for 40 seconds. With this patch, application observed a worst case latency of twice the replication round trip time. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| drbd_actlog.c | ||
| drbd_bitmap.c | ||
| drbd_int.h | ||
| drbd_interval.c | ||
| drbd_interval.h | ||
| drbd_main.c | ||
| drbd_nl.c | ||
| drbd_nla.c | ||
| drbd_nla.h | ||
| drbd_proc.c | ||
| drbd_protocol.h | ||
| drbd_receiver.c | ||
| drbd_req.c | ||
| drbd_req.h | ||
| drbd_state.c | ||
| drbd_state.h | ||
| drbd_strings.c | ||
| drbd_strings.h | ||
| drbd_vli.h | ||
| drbd_worker.c | ||