On Tue, Apr 18, 2017 at 08:38:15PM +0300, Leon Romanovsky wrote: > On Tue, Apr 18, 2017 at 11:28:52AM -0600, Jason Gunthorpe wrote: > > On Tue, Apr 18, 2017 at 06:52:00PM +0300, Yishai Hadas wrote: > > > > We could use a hash scheme or something to multiple the lock, but I'm > > really not sure that 32 bit performance matters to anyone anymore? > > In a hard way, I learned that we have a customer who expects that his 32bit > application will continue to work, so the answer is - no, I care. Of course it continues to work. Does your customer fit this very narrow definition: - Would actually upgrade to rdma-core - 32 bit - No SSE hardware (any Intel chip capable of PCI-E has SSE hardware) - Multiple same-provider devices with a single program touching all devices (single device performance is unchanged) - Sensitive to the performance difference of a potential spinlock contention / cache misplacement for ~4 instructions It is hard to understand who cares so much about peformance but leaves a wack on the table by running in 32 bit mode. Is this something like x32? We can certainly improve for x32. PPC32 could also potentially have a path like SSE.. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
