On Sun, 10 Dec 2006, Marco Costalba wrote: > > Ok. Perhaps I'm doing something wrong but the following code it's > always 10% slower then the temporary file one (4.7s against 4.3s for > linux tree) Why do you seem to be doing a "new" on every iteration inside the loop? Also, why do you have that strange FILE_BLOCK_SIZE thing, and in particular the "if (len < FILE_BLOCK_SIZE)" check? One thing that pipes vs files do is the blocking factor. Especially with older kernels, I _guarantee_ you that you'll only ever get 4kB at a time, so because of that "if (len < 64kB) break" thing, the only thing you're doing is to make sure things suck performance-wise, and you won't be reading the rest of the data until 100ms later. IOW, your code is written for a file, and makes no sense there either (checking "feof(file)" is wrong, since you may well have hit the EOF *at*that*time*, but the file may GROW since you are doing it all in the background, so you can't rely on feof() anyway). For a pipe, what you should do is to make sure it's in nonblocking mode, and just continue reading until it gets no more. And instead of using a timeout, you should use poll() or something to get notified when there is more data. IOW, the reason it's slow is because you're doing the wrong thing. Linus - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html