On Wed, Sep 7, 2011 at 1:36 PM, <Shyam_Iyer@xxxxxxxx> wrote: > > >> -----Original Message----- >> From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Jon Mason >> Sent: Wednesday, September 07, 2011 2:49 PM >> To: Benjamin Herrenschmidt >> Cc: Jesse Barnes; linux-pci@xxxxxxxxxxxxxxx >> Subject: Re: [PATCH] PCI: Remove MRRS modification from MPS setting >> code >> >> On Sep 6, 2011 1:47 PM, "Benjamin Herrenschmidt" >> <benh@xxxxxxxxxxxxxxxxxxx> wrote: >> > On Tue, 2011-09-06 at 12:12 -0700, Jon Mason wrote: >> >> > Are these typically hitting with the "performance" option ? IE. It >> >> make >> >> > sense to leave MRRS untouched in the "safe" case. >> >> >> >> The patch I sent out still used the "performance" option without >> >> modifying the default MRRS of the device. All that have tested it >> >> said that it resolves their issues. >> > >> > But that will cause other issues as I described, if the MRRS end up >> > larger than the MPS. IE. The MRRS of a device must be set to be lower >> or >> > equal to the MPS of that device (not of the parent btw) if we allow >> the >> > parent(s) to have a larger MPS. >> >> Yes, that is the hole. >> >> > I -did- hit a very real problem with adapters where that wasn't true. >> > >> > As for those users, are they all the same radeon ? >> >> hpsa users too. Also, some Dell servers are experiencing issues, but >> I am not sure what hardware is causing issue on those systems. Based >> on this thread, I believe the best way to move forward is to make the >> "safe" option the default and have it not set the MRRS. The >> "performance" option will set the MRRS. I will add a printk to notify >> the user of potential issues. Hopefully users will try this option >> and inform us of any issues encountered. > > A parameter option may help the cause for folks who would rather like the performance option. A boot parm already exists, pci=pcie_bus_perf. > >> >> Thoughts? >> >> Thanks, >> Jon >> >> > Cheers, >> > Ben. >> > >> > >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
