From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: Flush warning Date: Sun, 13 Aug 2017 09:46:51 +0300 Message-ID: <20170813064651.GR24282@mtr-leonro.local> References: <016301d30c86$e7034ae0$b509e0a0$@opengridcomputing.com> <9bc142de-b8ba-acb6-5ea1-2ccdbb578655@grimberg.me> <003401d30f91$c7e2a3f0$57a7ebd0$@opengridcomputing.com> <00ff01d3112b$94142350$bc3c69f0$@opengridcomputing.com> <20170809162749.GA4069@obsidianresearch.com> <011601d3112d$fa305b70$ee911250$@opengridcomputing.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="5FetH82qe0Z6y/zI" Return-path: Content-Disposition: inline In-Reply-To: <011601d3112d$fa305b70$ee911250$@opengridcomputing.com> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Steve Wise Cc: 'Jason Gunthorpe' , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, 'Sean Hefty' , 'Sagi Grimberg' , linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, 'Christoph Hellwig' List-Id: linux-rdma@vger.kernel.org --5FetH82qe0Z6y/zI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Aug 09, 2017 at 11:38:49AM -0500, Steve Wise wrote: > > On Wed, Aug 09, 2017 at 11:21:38AM -0500, Steve Wise wrote: > > > > > > I don't know. I read the workqueue doc on WQ_MEM_RECLAIM, but I don't > > know > > > > how > > > > to tell if iw_cm needs this or not. Can you give me an example of a > workqueue > > > > that _does_ need WQ_MEM_RECLAIM? I _think_ it means your workqueue is > > > > required > > > > to run something that would get triggered by the oom OS code, but I don't > know > > > > if that would include rdma CMs or not... > > > > > > Many of the workqueues in infiniband/core use WQ_MEM_RECLAIM: cma, iwcm, > > mad, > > > multicast, sa_query, and ucma. > > > > > > Hey Sean, do you have any insight into whether the CMA modules really need > > > WQ_MEM_RECLAIM for their workqueues? > > > > > > Does anyone else know? > > > > Consider that the ib_core can be used to back storage. Ie consider a > > situation where iSER/NFS/SRP needs to reconnect to respond to kernel > > paging/reclaim. > > > > On the surface it seems reasonable to me that these are on a reclaim > > path? > > > > Jason > > hmm. That seems reasonable. Then I would think the nvme_rdma would also need > to be using a reclaim workqueue. > > Sagi, Do you think I should add a private workqueue with WQ_MEM_RECLAIM to > nvme_rdma vs using the system_wq? nvme/target probably needs one also... The workqueue which frees the memory and doesn't allocate memory during execution is supposed to be marked as WQ_MEM_RECLAIM. This flag will cause to priority increase for such workqueue during low memory conditions. I don't remember it for sure, but I think that shrinker will call to such workqueue in these conditions. In normal conditions, it won't change a lot. Thanks > > Steve. > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --5FetH82qe0Z6y/zI Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkhr/r4Op1/04yqaB5GN7iDZyWKcFAlmP9dsACgkQ5GN7iDZy WKcoxxAAzMWxrw4CoIUvF/7w3joFU4j+mzO/E0X6A9ZjVdMudfo1ookTm40zg2IP Iq9rjtr56erpsi/8wjN5Th8OPAcASHhZ621jFKjODfUGwFXFlNPvW7LAruxPA4w6 BNl5TMmjdCdZlAwJAwF7/Co3t/rAkZgmsu5+2W2QWxji6akBLlymMXQP8sN+YxRz mH8QEgqPvihXUWqxetlRKghlUpIbP87hBAAZRHxF7xe46tMDVQowPhGU8TfuTojv UI2JrH9C6rdJ9TijR95Ct4uiZTiyvWBeQJyN9zN7jcv+HflPoMsHsGXDEExKfgdx mhMjnZFJ6GmOO2In9JK/eQx1PGObRCxLT+HIiDntRRT1R3lvLNIX+86lsLgKLkXU 2q0HT9HBpsmZ/7kPBnJYx+ddKr/oHByqananoiGrgDMQZP//Db31+vKrLjBzmpql KdxTIpmDB2L4gyojQaMj6CIhUOy1ipLE8aL12HIIgqn6a1q0IRmmcCJ1uLXE6R2j kGRMAKB/jZF+m6yrCKHBDJ+/j4DFxqYpSJvBF2m/VlGPZuogH2ZcqGAQtHwUzpoJ YdhWgWsGAWNwds4XGRKPmJrYTfyXiKGMdY0CHf9zXK1bact3ruf9x82ZC+u2nYNw odD9ksHo21QieAdB2Dpc/mIvC+/kIrTW29SoFJE8u2W287qVyDo= =eF5E -----END PGP SIGNATURE----- --5FetH82qe0Z6y/zI-- -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html