Karim Yaghmour wrote: > This is not good for any client that doesn't know beforehand the exact > size of their data units, as in the case of LTT. If LTT has to use this > code that means we are going to loose performance because we will need to > fill an intermediate data structure which will only be used for relay_write(). > Instead of zero-copy, we would have an extra unnecessary copy. There has > got to be a way for clients to directly reserve and write as they wish. > Even Zach Brown recognized this in his tracepipe proposal, here's from > his patch: > + * - let caller reserve space and get a pointer into buf
Actually, come to think of it, this code is not good for any client that needs to fill complex data structures, whether they be fixed-size or not, because it requires having a prepackaged structure already available. Any client that wants to have zero-copying will want to write data directly into the buffer instead of filling an intermediate buffer first. And this requires being able to atomically reserve. Karim -- Author, Speaker, Developer, Consultant Pushing Embedded and Real-Time Linux Systems Beyond the Limits http://www.opersys.com || [EMAIL PROTECTED] || 1-866-677-4546 - 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/
