On Tue, Apr 18, 2017 at 12:17:36PM -0600, Jason Gunthorpe wrote: > 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. It doesn't matter if customer cares or not cares about performance. We as a company provided satisfactory numbers to them and would like to ensure that these numbers don't reduce over time. I'm not looking for a performance boost in 32bit environment, but I don't expect decrease either. > > Is this something like x32? We can certainly improve for x32. From the customer ticket, the system is x86 (32 bits). > > PPC32 could also potentially have a path like SSE.. > > Jason
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