30/10/2020 16:35, McDaniel, Timothy: > From: Thomas Monjalon <tho...@monjalon.net> > > 30/10/2020 12:58, McDaniel, Timothy: > > > From: McDaniel, Timothy > > > > From: Thomas Monjalon <tho...@monjalon.net> > > > > > 30/10/2020 10:43, Timothy McDaniel: > > > > > > - note that the code still uses its private byte-encoded versions of > > > > > > umonitor/umwait, rather than the new functions in the power > > > > > > patch that are built on top of those intrinsics. This is > > > > > > intentional. > > > > > > > > > > Why? Now these intrinsics are available in the main branch. > > > > > We should avoid duplicating such code. > > > > > > > > > > > > > > > > > > I had asked that the low level intrinsics (UMWAIT/UMONITOR) be split > > > > out so > > > > that DLB/DLB2 could use them instead of its own private byte-encoded > > versions, > > > > but instead we have these wrappers that call the low level intrinsics. > > > > Those > > > > wrappers > > > > introduce additional overhead that is not required for DLB/DLB2. I have > > > > a > > > > meeting with Ma Liang on Monday to discuss. > > > > > > I thought the ask of DLB was to just substitute the low level > > > umwait/umonitor > > byte > > > encoded instructions DLB has defined privately with similar byte-encoded > > instructions defined in the power > > > patch. The power patch does not directly expose those, which is why I did > > > not > > update DLB/DLB2. > > > The power patch does have the advantage of centralizing the race avoidance > > > logic, which is a good thing for any PMD that wishes to take advantage of > > umwait/umonitor. > > > > So you mean the overhead is a good thing? > > > > > Sorry for the confusion. I just misunderstood what was being asked of DLB > > > in > > regard to switching over.. That being said, > > > I am willing to convert DLB/DLB2 to use rte_power_monitor(...) in a > > > future > > patch-set. > > > > Why not now? > > > > Indeed there is a confusion and it looks like a lot of novlang > > to exit from the situation. > > We'll wait a clear decision with facts. > > > > Hi Thomas, > > I have updated DLB and DLB2 to use rte_power_monitor(...), and those patches > are > ready if you are willing to accept them and the 3 power patches. > > For the sake of consistency, I see the benefit of using the power patch, even > if it is > slightly less efficient that the DLB-specific implementation that I currently > have. > We have already encountered an empty queue, so this is no longer fast path > for the PMD.
I am really concerned that the API in EAL is not the most efficient. Why is that? Can we improve the EAL API?
