> -----Original Message----- > From: Felix Fietkau <nbd@xxxxxxxx> > Sent: Saturday, December 4, 2021 1:55 PM > To: Sriram R (QUIC) <quic_srirrama@xxxxxxxxxxx>; linux- > wireless@xxxxxxxxxxxxxxx > Cc: johannes@xxxxxxxxxxxxxxxx > Subject: Re: [RFC] mac80211: Mesh Fast xmit support > > WARNING: This email originated from outside of Qualcomm. Please be wary > of any links or attachments, and do not enable macros. > > On 2021-12-04 03:04, Sriram R wrote: > > Support Fast xmit for mesh device types by caching the header > > corresponding to the ethernet DA and reusing the cached header (mac, > > mesh, llc) everytime the packet is intended for that DA. > > > > This will avoid multiple path table lookups during header generation > > for a mesh packet tx. > > > > Freshness of the header is verified by identifying change in mesh > > paths before using the header and corresponding changes to the header > > and cache entry is done on the fly. > > > > Mutable fields of the header such as eth SA, tid, mesh SN, PN are > > updated for each xmit. > > > > Each cache entry is about 100Bytes, least used/expired entries are > > periodically removed when cache gets almost full. > > Currently the size is set to 50 entries. > > > > Driver needs to advertise NL80211_EXT_FEATURE_MESH_FAST_XMIT > > to enable this support and setup this cache. > Thanks for working on this! I will likely take a closer look at it soon. > One quick question: does this impose any extra requirements on the driver, > or why does the driver need to advertise support for this? Hi Felix, There is no requirement from driver/hw as such and this has similar requirement as IEEE80211_HW_SUPPORT_FAST_XMIT being enabled from driver. But I was not sure if adding ~5KB (50 entries x ~100Bytes) by default was acceptable for those drivers which already enabled FAST_XMIT. Hence added this extra control from driver to enable this feature for this RFC. Kindly suggest if other alternatives could be taken up. Regards, Sriram.R > > - Felix
