From: Roland Dreier <rdreier-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
To: Sean Hefty <sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Steve Wise
<swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>,
linux-rdma <linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: Problem with RDMA device removal architecture
Date: Fri, 26 Mar 2010 16:00:05 -0700 [thread overview]
Message-ID: <adad3yqy9hm.fsf@roland-alpha.cisco.com> (raw)
In-Reply-To: <06FEECB9AB064B309D21BA9AC0A4BFFD-Zpru7NauK7drdx17CPfAsdBPR1lH4CV8@public.gmane.org> (Sean Hefty's message of "Fri, 26 Mar 2010 15:54:58 -0700")
> >uverbs is trickier, because a userspace process will typically have some
> >hardware resources directly mmap'ed. We need a way to "revoke" that
> >mmap and have it point at a dummy page until userspace releases it --
> What exactly would the dummy page contain and could the application/library read
> it assuming that it is obtaining valid data?
It would be an all-0s page I guess (to avoid leaking kernel data).
What the device driver library would do with it is device-specific but
eg Mellanox uses it write-only. Not sure if any other devices put
something readable there -- if so I guess that driver should put a safe
value there if possible.
--
Roland Dreier <rolandd-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
For corporate legal information go to:
http://www.cisco.com/web/about/doing_business/legal/cri/index.html
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next prev parent reply other threads:[~2010-03-26 23:00 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-26 15:57 Problem with RDMA device removal architecture Steve Wise
[not found] ` <4BACD985.1070906-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 16:16 ` Sean Hefty
[not found] ` <DAF23AFA2B904B32B418D9C8798D4276-Zpru7NauK7drdx17CPfAsdBPR1lH4CV8@public.gmane.org>
2010-03-26 16:36 ` Steve Wise
[not found] ` <4BACE28A.2080409-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 16:50 ` Tung, Chien Tin
[not found] ` <603F8A3875DCE940BA37B49D0A6EA0AE84CFD851-uLM7Qlg6Mbekrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2010-03-26 16:59 ` Steve Wise
[not found] ` <4BACE7E8.3040803-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 17:29 ` Tung, Chien Tin
[not found] ` <603F8A3875DCE940BA37B49D0A6EA0AE84CFD8DD-uLM7Qlg6Mbekrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2010-03-26 17:58 ` Steve Wise
[not found] ` <4BACF5B8.7090304-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 18:05 ` Steve Wise
2010-03-26 17:08 ` Roland Dreier
[not found] ` <adazl1vxb7p.fsf-BjVyx320WGW9gfZ95n9DRSW4+XlvGpQz@public.gmane.org>
2010-03-26 17:47 ` Steve Wise
2010-03-26 18:29 ` Steve Wise
[not found] ` <4BACFCF5.6030501-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 18:55 ` Roland Dreier
[not found] ` <adask7myktq.fsf-BjVyx320WGW9gfZ95n9DRSW4+XlvGpQz@public.gmane.org>
2010-03-26 19:01 ` Steve Wise
[not found] ` <4BAD047A.1000408-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 18:59 ` Roland Dreier
[not found] ` <adaociaykn1.fsf-BjVyx320WGW9gfZ95n9DRSW4+XlvGpQz@public.gmane.org>
2010-05-21 18:06 ` Steve Wise
[not found] ` <4BF6CBAA.5020906-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-05-21 18:30 ` Roland Dreier
2010-03-26 20:18 ` Tung, Chien Tin
[not found] ` <603F8A3875DCE940BA37B49D0A6EA0AE84CFDB38-uLM7Qlg6Mbekrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2010-03-26 20:45 ` Roland Dreier
2010-03-26 22:54 ` Sean Hefty
[not found] ` <06FEECB9AB064B309D21BA9AC0A4BFFD-Zpru7NauK7drdx17CPfAsdBPR1lH4CV8@public.gmane.org>
2010-03-26 23:00 ` Roland Dreier [this message]
2010-03-26 17:08 ` Sean Hefty
[not found] ` <AB19885D9F4245DFABBCB131959382C5-Zpru7NauK7drdx17CPfAsdBPR1lH4CV8@public.gmane.org>
2010-03-26 17:42 ` Steve Wise
2010-03-26 16:47 ` Tung, Chien Tin
[not found] ` <603F8A3875DCE940BA37B49D0A6EA0AE84CFD841-uLM7Qlg6Mbekrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2010-03-26 16:53 ` Steve Wise
[not found] ` <4BACE695.4010006-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2010-03-26 17:02 ` Tung, Chien Tin
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