On Wed, Dec 18, 2013 at 04:01:04PM +0200, Alexander Shishkin wrote: > > Why don't you start by explaining _why_ you need a second stream to > > begin with? > > Oh, I'm sure I've explained it earlier ([1], [2])
See, I didn't read 0 because that information gets lost and patches should be self explanatory, and i didn't get to the Intel driver yet because well, I got stuck in the generic code. > but why not. The data > in the second stream is generated at a rate which is hundreds of > megabytes per second per core. Decoding this data is ~1000 times slower > than generating it. Ergo, can't be done in kernel, needs to be exported > as-is to userspace for later retreival and decoding. Doing it via perf > stream means an extra copy, which at these rates is a waste. Ergo, a > second buffer. Still confused, if you cannot copy it into one buffer, then why can you copy it into a second buffer? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/