Quoting r. Greg Lindahl <[EMAIL PROTECTED]>: > Subject: Help with CONFIG_PCI_MSI in the kernel > > Red Hat has started turning off CONFIG_PCI_MSI in their kernels (FC5 > and the latest FC4 update). I remember a while back there was a > discussion about how MSI made the Mellanox HCA run faster, can someone > please add some concrete details about this to the bug? Thanks. > > http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=186520
Unfortunately its not a clear-cut win, or not on all systems. At least for me, IRQ rebalancing seems to work much worse with MSI than with regular interrupt messages: the interrupts seem to bounce between CPUs all the time. I am only getting good performance from MSI by disabling IRQ rebalancing and binding the task to a specific CPU. It works fine with regular interrupts and I never had the time to get to the bottom of it. -- Michael S. Tsirkin Staff Engineer, Mellanox Technologies _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
