linux-kernel - Re: [openib-general] [PATCH v4 01/13] Linux RDMA Core Changes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <adawt424gt8.fsf@cisco.com>
Date:	Thu, 04 Jan 2007 13:34:27 -0800
From:	Roland Dreier <rdreier@...co.com>
To:	Steve Wise <swise@...ngridcomputing.com>
Cc:	"Michael S. Tsirkin" <mst@...lanox.co.il>, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, openib-general@...nib.org
Subject: Re: [openib-general] [PATCH  v4 01/13] Linux RDMA Core Changes

OK, I'm back from vacation today.

Anyway I don't have a definitive statement on this right now.  I guess
I agree that I don't like having an extra parameter to a function that
should be pretty fast (although req notify isn't quite as hot as
something like posting a send request or polling a cq), given that it
adds measurable overhead.  (And I am surprised that the overhead is
measurable, since 3 arguments still fit in registers, but OK).

I also agree that adding an extra entry point just to pass in the user
data is ugly, and also racy.

Giving the kernel driver a pointer it can read seems OK I guess,
although it's a little ugly to have a backdoor channel like that.

I'm somewhat surprised the driver has to go into the kernel to rearm a
CQ -- what makes the operation need kernel privileges?  (Sorry for not
reading the code)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/