All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Jinpu Wang <jinpu.wang@cloud.ionos.com>
Cc: Bart Van Assche <bvanassche@acm.org>,
	Danil Kipnis <danil.kipnis@cloud.ionos.com>,
	Jack Wang <jinpuwang@gmail.com>,
	linux-block@vger.kernel.org, linux-rdma@vger.kernel.org,
	Jens Axboe <axboe@kernel.dk>,
	Christoph Hellwig <hch@infradead.org>,
	Sagi Grimberg <sagi@grimberg.me>,
	Leon Romanovsky <leon@kernel.org>,
	Doug Ledford <dledford@redhat.com>,
	Roman Penyaev <rpenyaev@suse.de>,
	Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Subject: Re: [PATCH v9 06/25] RDMA/rtrs: client: main functionality
Date: Thu, 5 Mar 2020 09:27:48 -0400	[thread overview]
Message-ID: <20200305132748.GH31668@ziepe.ca> (raw)
In-Reply-To: <CAMGffEncbGXhFLDxZJp957c7vmV4vCaTZFUVKwqDROFikCTLPg@mail.gmail.com>

On Thu, Mar 05, 2020 at 12:26:01PM +0100, Jinpu Wang wrote:

> We have to admit, the code snip is from null_blk, get_tag function,
> not invented by us.
> the get_cpu/put_cpu was added to get/save the current cpu_id, which
> can be removed around the do-while loop.,
> we only need to raw_smp_processor_id to get current cpu, we use it
> later to pick which connection to use.

Be careful copying crazy core code into drivers.. 

> > You have to do something to provably guarantee the send q cannot
> > overflow. send q overflow is defined as calling post_send before a
> > poll_cq has confirmed space is available for send.

> Shouldn't the cq api handle that already,  with IB_POLL_SOFTIRQ,
> poll cq is done on very softirq run, so send queue space should be reclaimed
> fast enough, with IB_POLL_WORKQUEUE, when cq->com_handler get called,
> the ib_cq_poll_work will do the poll_cq, together with extra
> send_queue size reserved,
> the send queue can not overflow!

Somehow that doesn't sound like 'provably guarentee' - that is some
statistical argument..

Jason

  reply	other threads:[~2020-03-05 13:27 UTC|newest]

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-21 10:46 [PATCH v9 00/25] RTRS (former IBTRS) RDMA Transport Library and RNBD (former IBNBD) RDMA Network Block Device Jack Wang
2020-02-21 10:46 ` [PATCH v9 01/25] sysfs: export sysfs_remove_file_self() Jack Wang
2020-03-01  0:24   ` Bart Van Assche
2020-03-02 14:37     ` Jinpu Wang
2020-02-21 10:46 ` [PATCH v9 02/25] RDMA/rtrs: public interface header to establish RDMA connections Jack Wang
2020-03-01  0:31   ` Bart Van Assche
2020-03-02  8:39     ` Jinpu Wang
2020-03-03  9:40   ` Leon Romanovsky
2020-03-03 14:05     ` Jinpu Wang
2020-03-03 14:16       ` Leon Romanovsky
2020-03-03 14:23         ` Jinpu Wang
2020-02-21 10:46 ` [PATCH v9 03/25] RDMA/rtrs: private headers with rtrs protocol structs and helpers Jack Wang
2020-03-01  0:37   ` Bart Van Assche
2020-03-02  9:21     ` Jinpu Wang
2020-03-03  9:45   ` Leon Romanovsky
2020-03-03 13:52     ` Jinpu Wang
2020-03-03 14:05       ` Jason Gunthorpe
2020-03-03 16:13         ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 04/25] RDMA/rtrs: core: lib functions shared between client and server modules Jack Wang
2020-03-01  0:47   ` Bart Van Assche
2020-03-02  8:40     ` Jinpu Wang
2020-03-03  9:57   ` Leon Romanovsky
2020-03-04 11:21     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 05/25] RDMA/rtrs: client: private header with client structs and functions Jack Wang
2020-03-01  0:51   ` Bart Van Assche
2020-03-02 13:49     ` Jinpu Wang
2020-03-02 16:13       ` Bart Van Assche
2020-03-02 16:18         ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 06/25] RDMA/rtrs: client: main functionality Jack Wang
2020-03-01  1:33   ` Bart Van Assche
2020-03-02 13:20     ` Danil Kipnis
2020-03-03 16:04       ` Bart Van Assche
2020-03-04 16:43         ` Jinpu Wang
2020-03-04 16:49           ` Jason Gunthorpe
2020-03-05 11:26             ` Jinpu Wang
2020-03-05 13:27               ` Jason Gunthorpe [this message]
2020-03-05 13:37                 ` Jinpu Wang
2020-03-05 13:54                   ` Jason Gunthorpe
2020-03-06 13:33                     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 07/25] RDMA/rtrs: client: statistics functions Jack Wang
2020-03-03 11:28   ` Leon Romanovsky
2020-03-03 11:46     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 08/25] RDMA/rtrs: client: sysfs interface functions Jack Wang
2020-02-21 10:47 ` [PATCH v9 09/25] RDMA/rtrs: server: private header with server structs and functions Jack Wang
2020-02-21 10:47 ` [PATCH v9 10/25] RDMA/rtrs: server: main functionality Jack Wang
2020-03-01  1:42   ` Bart Van Assche
2020-03-02 14:39     ` Jinpu Wang
2020-03-03 11:37   ` Leon Romanovsky
2020-03-03 16:41     ` Jinpu Wang
2020-03-03 16:59       ` Leon Romanovsky
2020-03-04 11:03         ` Jinpu Wang
2020-03-05  8:00           ` Leon Romanovsky
     [not found]             ` <CAHg0Huyc=pn1=WSKGLjm+c8AcchyQ8q7JS-0ToQyiBRgpGG=jA@mail.gmail.com>
2020-03-05 12:16               ` Leon Romanovsky
2020-03-05 12:28                 ` Jinpu Wang
2020-03-05 12:35                   ` Leon Romanovsky
2020-03-05 13:02                     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 11/25] RDMA/rtrs: server: statistics functions Jack Wang
2020-02-21 10:47 ` [PATCH v9 12/25] RDMA/rtrs: server: sysfs interface functions Jack Wang
2020-02-21 10:47 ` [PATCH v9 13/25] RDMA/rtrs: include client and server modules into kernel compilation Jack Wang
2020-02-21 10:47 ` [PATCH v9 14/25] RDMA/rtrs: a bit of documentation Jack Wang
2020-02-21 10:47 ` [PATCH v9 15/25] block/rnbd: private headers with rnbd protocol structs and helpers Jack Wang
2020-03-01  2:12   ` Bart Van Assche
2020-03-02 16:37     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 16/25] block/rnbd: client: private header with client structs and functions Jack Wang
2020-03-01  2:26   ` Bart Van Assche
2020-03-02 14:59     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 17/25] block/rnbd: client: main functionality Jack Wang
2020-03-01  2:46   ` Bart Van Assche
2020-03-02 14:58     ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 18/25] block/rnbd: client: sysfs interface functions Jack Wang
2020-02-21 10:47 ` [PATCH v9 19/25] block/rnbd: server: private header with server structs and functions Jack Wang
2020-03-01  2:47   ` Bart Van Assche
2020-03-02 10:07     ` Danil Kipnis
2020-02-21 10:47 ` [PATCH v9 20/25] block/rnbd: server: main functionality Jack Wang
2020-03-01  2:58   ` Bart Van Assche
2020-03-02  9:58     ` Danil Kipnis
2020-03-03  5:57       ` Bart Van Assche
2020-02-21 10:47 ` [PATCH v9 21/25] block/rnbd: server: functionality for IO submission to file or block dev Jack Wang
2020-03-01  3:09   ` Bart Van Assche
2020-03-02 10:06     ` Danil Kipnis
2020-03-03 16:20       ` Jinpu Wang
2020-03-03 16:28         ` Bart Van Assche
2020-03-03 16:43           ` Jinpu Wang
2020-02-21 10:47 ` [PATCH v9 22/25] block/rnbd: server: sysfs interface functions Jack Wang
2020-02-21 10:47 ` [PATCH v9 23/25] block/rnbd: include client and server modules into kernel compilation Jack Wang
2020-02-21 10:47 ` [PATCH v9 24/25] block/rnbd: a bit of documentation Jack Wang
2020-02-21 10:47 ` [PATCH v9 25/25] MAINTAINERS: Add maintainers for RNBD/RTRS modules Jack Wang
2020-03-03  9:28 ` [PATCH v9 00/25] RTRS (former IBTRS) RDMA Transport Library and RNBD (former IBNBD) RDMA Network Block Device Leon Romanovsky
2020-03-04 14:06   ` Jinpu Wang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200305132748.GH31668@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=axboe@kernel.dk \
    --cc=bvanassche@acm.org \
    --cc=danil.kipnis@cloud.ionos.com \
    --cc=dledford@redhat.com \
    --cc=hch@infradead.org \
    --cc=jinpu.wang@cloud.ionos.com \
    --cc=jinpuwang@gmail.com \
    --cc=leon@kernel.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=pankaj.gupta@cloud.ionos.com \
    --cc=rpenyaev@suse.de \
    --cc=sagi@grimberg.me \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.