On Thu, Dec 19, 2013 at 09:53:44AM +0200, Alexander Shishkin wrote: > Peter Zijlstra <[email protected]> writes: > > The thing is; why can't you zero-copy whatever buffer the hardware > > writes into, into the normal buffer? > > I'm not sure I understand. You mean, have the buffer split between perf > data and trace data?
Yep, I don't see any reason why this wouldn't work. When the hardware thing sends an interrupt to notify us its buffer is 'full', stop the recorder, try to create a single record in the buffer that's big enough + 1 page, then swizzle the hardware pages and the buffer pages for that record, using the +1 page to page align the actual data. Then (re)start the hardware on the 'new' pages. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
