> From: Morten Brørup > Sent: Thursday, 11 December 2025 22.45 > > > From: Bruce Richardson [mailto:[email protected]] > > Sent: Wednesday, 10 December 2025 18.01 > > > > On Mon, Aug 11, 2025 at 02:47:17PM +0200, Morten Brørup wrote: > > > > From: Morten Brørup [mailto:[email protected]] > > > > Sent: Tuesday, 24 June 2025 08.13 > > > > > > > > When fast releasing mbufs, the mbufs are not accessed, so do not > > prefetch > > > > them. > > > > This saves a mbuf load operation for each fast released TX mbuf. > > > > > > > > When fast release of mbufs is enabled for a TX queue, cache the > > mbuf > > > > mempool pointer in the TX queue structure. > > > > This saves one mbuf load operation for each burst of fast > released > > TX > > > > mbufs. > > > > > > > > The txep->mbuf pointer is not used after the mbuf has been freed, > > so do > > > > not reset the pointer. > > > > This saves a txep store operation for each TX mbuf freed. > > > > > > > > Signed-off-by: Morten Brørup <[email protected]> > > > > --- > > > > > > After further consideration, I think this patch should be split in > > two: > > > 1. Remove superfluous code: prefetching mbufs and resetting txep- > > >mbuf pointers. > > > 2. Cache the mbuf mempool pointer for FAST_FREE. > > > > > Hi Morten, > > > > any plans for a new version of this patch (split or otherwise)? This > is > > popped up again on my list in patchwork and want to decide what to do > > with > > it for this release. :-) > > > > /Bruce > > I'll give it another shot. > > I took another look at it today, and it looks like the txep->mbuf (i.e. > sw_ring[].mbuf) is used by other cleanup functions, so not NULL'ing it > needs more detailed review. > > Anyway, prefetching the mbufs is a complete waste for fast free, where > the mbufs are not being accessed at all. So there's still something to > gain here. > > Also, my assumption that txq->offloads is hotter than txq->fast_free_mp > seems not to hold either, so I'll play around with that too. > > I'm considering sending a series of patches with very small steps, so > the individual changes are easy to review. > > -Morten
Turns out the "common" part of the Intel drivers entangles the i40e patch with other Intel drivers, so I sent a generic patch covering all of those, and marked this one as Superseded. -Morten
