Branch: refs/heads/peer-wq
Home: https://github.com/sheepdog/sheepdog
Commit: 15f5c9d3678f2c55390efa186963c0abbdf06e3e
https://github.com/sheepdog/sheepdog/commit/15f5c9d3678f2c55390efa186963c0abbdf06e3e
Author: Hitoshi Mitake <mitake.hito...@lab.ntt.co.jp>
Date: 2017-02-16 (Thu, 16 Feb 2017)
Changed paths:
M sheep/request.c
M sheep/sheep.c
M sheep/sheep_priv.h
Log Message:
-----------
sheep: create a dedicated workqueue for peer requests
Current sheepdog uses the io workqueue (sys->io_wqueue) for 2 kinds of
requests: peer and local. However, this architecture can cause
deadlock in the fixed workqueue mode because of the schedules like
below:
1. node A receives a request Ra from a client, queue Ra to io_wqueue
as a peer request
2. node B receives a request Rb from another client, queue Rb to
io_wqueue as a peer request
3. in node A, Ra forwards the requests to node B
4. in node B, Rb forwards the requests to node A
5. if node A or node B don't have idle workers in io_workqueue, it can
cause deadlock
This commit avoids the problem by creating a new dedicated workqueue
sys->peer_wqueue for avoiding the problem.
Signed-off-by: Hitoshi Mitake <mitake.hito...@lab.ntt.co.jp>
--
sheepdog mailing list
sheepdog@lists.wpkg.org
https://lists.wpkg.org/mailman/listinfo/sheepdog
