From mboxrd@z Thu Jan 1 00:00:00 1970 From: olivier.mallinger@ip-maker.com (Olivier Mallinger - IP Maker) Date: Thu, 05 Mar 2015 16:24:41 +0100 Subject: Testing IO PRP List In-Reply-To: References: <54F867BD.6070806@ip-maker.com> Message-ID: <54F87539.2050605@ip-maker.com> I agree with you concerning the testability of this feature under Linux. All my investigation lead to the same conclusion. I will try to test it with an other OS, checking if queue are created with PRP List. The best solution would be a PCIe exerciser but I don't have access to such equipment now. Thanks for your quick answer. Best regards. Olivier. Le 05/03/2015 16:12, Keith Busch a ?crit : > On Thu, 5 Mar 2015, Olivier Mallinger - IP Maker wrote: >> Continuing my investigation to test NVMe feature, I am looking for a >> way to test IO PRP List. >> >> Basically, the driver only creates contiguous queue for both >> submission and completion queues. >> To test, I wanted to use nvme-cli to do the following : >> 1 - Delete one IO submission queue using "admin-passthru" command >> 2 - Delete one IO completion queue using "admin-passthru" command >> 3 - Create one IO completion queue using "admin-passthru" command >> with support of PRP List >> 4 - Create one IO submission queue using "admin-passthru" command >> with support of PRP List >> 5 - Perform many IO read and write to check IO PRP List behavior > > I don't think you should delete or create queues from userspace. > Deleting them out from under the driver is just going to confuse it > when IO stops working. Creating isn't safe since the user address for > the queue is pinned in memory only while the passthrough command is in > flight. Plus the queue memory is freed when the "nvme" program exits > anyway, but the h/w queue still exists. > > The driver does not do any interpretation what-so-ever on passthroughs, > so while it is possible to send those commands, it's not going to do > what I think you're looking for. > > There's no reason I know of to add support for physically discontiguous > IO queues in the Linux driver, so I don't think this feature is testable > in this environment. -------------- next part -------------- A non-text attachment was scrubbed... Name: olivier_mallinger.vcf Type: text/x-vcard Size: 316 bytes Desc: not available URL: