On Wed, Aug 05, 2020 at 07:28:50PM +0300, Max Gurtovoy wrote: > > On 8/5/2020 7:06 PM, Leon Romanovsky wrote: > > On Wed, Aug 05, 2020 at 06:14:16PM +0300, Max Gurtovoy wrote: > > > On 8/5/2020 4:16 PM, Leon Romanovsky wrote: > > > > On Wed, Aug 05, 2020 at 03:12:30PM +0300, Max Gurtovoy wrote: > > > > > Add performance optimization that might slightly improve small IO sizes > > > > > benchmarks. > > > > > > > > > > Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx> > > > > > --- > > > > > drivers/infiniband/ulp/isert/ib_isert.c | 4 ++-- > > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > I find the expectation from "unlikely/likely" keywords to be overrated. > > > > > > > > When we introduced dissagregate post send verbs in rdma-core, we > > > > benchmarked likely/unlikely and didn't find any significant difference > > > > for code with and without such keywords. > > > > > > > > Thanks > > > Leon, > > > > > > We are using these small optimizations in all our ULPs and we saw benefit in > > > large scale and high loads (we did the same in NVMf/RDMA). > > > > > > These kind of optimizations might not be seen immediately but are > > > accumulated. > > > > > > I don't know why do you compare user-space benchmarks to storage drivers. > > Why not? It produces same asm code and both have same performance > > characteristic. > > > > > Can you please review the code ? > > There is nothing to review here, the patch is straightforward, I just > > don't believe in it. > > Its ok. > > Just ignore it if you don't want to review it. OK, just because you asked. I reviewed this patch and didn't find any justification for performance claim, can you please provide us numbers before/after so we will be able to decide based on reliable data? It will help us to review our drivers and improve them even more. > > The maintainers of iser target will review and decide if they believe in it > or not. Sure, I don't care who will provide numbers. Thanks > > > > > Sagi, > > > > > > Can you send your comments as well ? > > > > > >
