Wen Gong <wgong@xxxxxxxxxxxxxxxx> writes: >> -----Original Message----- >> From: Dave Taht <dave@xxxxxxxx> >> Sent: Wednesday, September 4, 2019 12:10 AM >> To: Wen Gong <wgong@xxxxxxxxxxxxxxxx>; ath10k@xxxxxxxxxxxxxxxxxxx; >> linux-wireless@xxxxxxxxxxxxxxx >> Subject: [EXT] Re: [PATCH 2/7] ath10k: change max RX bundle size from 8 to >> 32 for sdio >> >> >> In terms of deeply grokking what increasing buffering to achieve high >> bandwidth on a testbench, vs what it can do to clobber latency in the >> real world at low bandwidths, I tend to point folk at: >> >> https://www.youtube.com/watch?v=Rb-UnHDw02o&t=25m40s >> >> where I got a whole bunch of hackers to stand up and act like packets >> in an aggregating FIFO wifi queue. >> >> This key section is only 8 minutes long, and I promise, y'all laugh >> at least 3 times at the demonstration. >> >> At the time, also, the ath10k was so overbuffered that on one test >> I could try to start 100 flows, and only get five. >> >> https://lwn.net/Articles/705884/ >> >> and on my slides: >> >> https://blog.linuxplumbersconf.org/2016/ocw//system/presentations/3963/ >> original/linuxplumbers_wifi_latency-3Nov.pdf >> > Hi Dave, > So your mean is change 8 to 32 will impact latency? It will increase latency of rx? Heh. for rx, in this case, probably not! I just get twitchy every time folk fiddle with buffer sizes. In one recent case someone had fiddled with the interrupt polling interval on something, going from 1ms to 10ms - it saved on cpu, but... ... just trying to make sure folk grok the tradoffs with a bit of laughter. carry on! > >> >> 0xFFFEFFFF
