Yes, I used an mpc8314 at 400Mhz, with 128 Mbit of RAM for my test. To find it, I measured the time elapsing in ath_rxbuf_alloc(..) with the kernel function local_clock(). With SLOB I found around 123 us (and I have an infinite loop in ath9k tasklet, because when I have consumed one packet the next packet is ready to rx process) With SLAB I found around 22 us With SLUB I found around 10 us Cedric Voncken -----Message d'origine----- De : adrian.chadd@xxxxxxxxx [mailto:adrian.chadd@xxxxxxxxx] De la part de Adrian Chadd Envoyé : mercredi 2 janvier 2013 17:22 À : voncken Cc : Felix Fietkau; Mohammed Shafi; linux-wireless@xxxxxxxxxxxxxxx Objet : Re: [RFC] ATH9K: infinite loop in Tasklet ... interesting. The allocator choice is enough to cause your CPU to run too far behind the workload? Adrian On 2 January 2013 05:17, voncken <cedric.voncken@xxxxxxxxx> wrote: > Thanks for your answer. > > I found a workaround for my problem. > > In my Linux kernel, the default SLAB allocator was changed in > default settings. > SLOB was used in place of SLAB. > I select the SLAB allocator and that fix the default because > it runs faster. > > However the infinite loop can still happen if the cpu is > heavily loaded with other tasklets. > > Best regards. > > Cedric Voncken > -----Message d'origine----- > De : adrian.chadd@xxxxxxxxx [mailto:adrian.chadd@xxxxxxxxx] De la part > de Adrian Chadd Envoyé : mercredi 2 janvier 2013 00:41 À : Felix > Fietkau Cc : Mohammed Shafi; Cedric VONCKEN; > linux-wireless@xxxxxxxxxxxxxxx Objet : Re: [RFC] ATH9K: infinite loop > in Tasklet > > On 1 January 2013 07:18, Felix Fietkau <nbd@xxxxxxxxxxx> wrote: > >> I think the best way to properly fix this issue is to implement NAPI >> support (which mac80211 already supports). > > Sure, but there may be some underlying issues (maybe even on just that > particular platform) that need to be addressed. > > Migrating to NAPI / breaking out of the tasklet early should also be > done, but it's potentially orthogonal to the OP's problem. > > > Adrian > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
