Nishanth Menon <nm@xxxxxx> writes: > From: Mans Rullgard <mans@xxxxxxxxx> > > Enabling L2 prefetching improves performance as shown on Panda > ES2.1 board with mem test, and it has measurable impact on > performances. I think we should consider it, even though it damages > "writes" a bit. (rebased to k.org) > Usually the prefetch is used at both levels together L1 + L2, however, > to enable the CP15 prefetch engines, these are under security, and on > GP devices, we cannot enable it(e.g. on PandaBoard). However, just > enabling PL310 prefetch seems to provide performance improvement, > as shown in the data below (from Ubuntu) and would be a great thing > to pull in. What this does is enable automatic next line prefetching. With this enabled, whenever the PL310 receives a cachable read request, it automatically prefetches the following cache line as well. A larger offset can be programmed in secure mode, but the TI ROM authors neglected to include this. Testing with FFmpeg showed a speedup of 10% with this patch in some cases. -- Måns Rullgård mans@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
