From: Sagi Grimberg <sagig-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
To: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH V2 10/17] xprtrdma: Add CONFIG setting that can disable ALLPHYSICAL
Date: Wed, 23 Apr 2014 13:24:35 +0300 [thread overview]
Message-ID: <535794E3.1020201@dev.mellanox.co.il> (raw)
In-Reply-To: <20140422062338.GA23311-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
On 4/22/2014 9:23 AM, Christoph Hellwig wrote:
> On Mon, Apr 21, 2014 at 06:02:14PM -0400, Chuck Lever wrote:
>> ALLPHYSICAL is not a safe memory registration mode because it
>> permits NFS servers to write anywhere in a client's memory. NFS
>> server bugs could result in client memory being overwritten.
>>
>> This can be useful for embedded systems which do not support more
>> surgical RDMA memory registration and protection methods, or for
>> bring-up of new HCA hardware.
>>
>> However, enterprise Linux distributions have expressed a desire to
>> disable it in production environments.
> It's just as unsafe in embedded devices. I think it should go
For small IOs pattern, ALLPHYSICAL should outperform any registration method
in terms of IOP rate (simply because it doesn't do it).
Generally speaking, deployments that may prefer higher IOP rate in the cost
of a security do exist out there...
Sagi.
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next prev parent reply other threads:[~2014-04-23 10:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-21 22:00 [PATCH V2 00/17] NFS/RDMA patches for review Chuck Lever
[not found] ` <20140421214442.12569.8950.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org>
2014-04-21 22:00 ` [PATCH V2 01/17] xprtrdma: mind the device's max fast register page list depth Chuck Lever
2014-04-21 22:01 ` [PATCH V2 02/17] nfs-rdma: Fix for FMR leaks Chuck Lever
2014-04-21 22:01 ` [PATCH V2 03/17] xprtrdma: Enable RDMA pad optimization by default Chuck Lever
[not found] ` <20140421220111.12569.77783.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org>
2014-04-22 15:05 ` Chuck Lever
2014-04-21 22:01 ` [PATCH V2 04/17] xprtrdma: RPC/RDMA must invoke xprt_wake_pending_tasks() in process context Chuck Lever
2014-04-21 22:01 ` [PATCH V2 05/17] xprtrdma: Remove BOUNCEBUFFERS memory registration mode Chuck Lever
2014-04-21 22:01 ` [PATCH V2 06/17] xprtrdma: Remove MEMWINDOWS registration modes Chuck Lever
2014-04-21 22:01 ` [PATCH V2 07/17] xprtrdma: Remove REGISTER memory registration mode Chuck Lever
2014-04-21 22:01 ` [PATCH V2 08/17] xprtrdma: Fall back to MTHCAFMR when FRMR is not supported Chuck Lever
2014-04-21 22:02 ` [PATCH V2 09/17] xprtrdma: mount reports "Invalid mount option" if memreg mode " Chuck Lever
2014-04-21 22:02 ` [PATCH V2 10/17] xprtrdma: Add CONFIG setting that can disable ALLPHYSICAL Chuck Lever
[not found] ` <20140421220214.12569.23157.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org>
2014-04-22 6:23 ` Christoph Hellwig
[not found] ` <20140422062338.GA23311-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2014-04-23 10:24 ` Sagi Grimberg [this message]
2014-04-21 22:02 ` [PATCH V2 11/17] xprtrdma: Simplify rpcrdma_deregister_external() synopsis Chuck Lever
2014-04-21 22:02 ` [PATCH V2 12/17] xprtrdma: Make rpcrdma_ep_destroy() return void Chuck Lever
2014-04-21 22:02 ` [PATCH V2 13/17] xprtrdma: Split the completion queue Chuck Lever
2014-04-21 22:02 ` [PATCH V2 14/17] xprtrmda: Reduce lock contention in completion handlers Chuck Lever
2014-04-21 22:02 ` [PATCH V2 15/17] xprtrmda: Reduce calls to ib_poll_cq() " Chuck Lever
2014-04-21 22:03 ` [PATCH V2 16/17] xprtrdma: Limit work done by completion handler Chuck Lever
[not found] ` <20140421220308.12569.43779.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org>
2014-04-23 10:15 ` Sagi Grimberg
2014-04-21 22:03 ` [PATCH V2 17/17] xprtrdma: Reduce the number of hardway buffer allocations Chuck Lever
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