On Tue, Sep 27, 2011 at 4:12 PM, Roedel, Joerg <Joerg.Roedel@xxxxxxx> wrote: > You pass a pointer to an unsigned long for the page-size bitmap. This > allows to use an array of unsigned long. But a single unsigned long is > sufficient This is fine; I can change that if you like it better (though without doing the change below this is probably moot). > and you can use functions like ffs() and fls() together with > shifting. These functions often translate to a single intruction in the > binary. The find_next_bit function has much more overhead because it > needs to handle the array-of-ulong case. So you're suggesting to re-implement find_next_bit() using ffs()/fls() and shifting ? What's the point ? Sure, if we'll have a proven performance issue while using find_next_bit() we can think of doing this, but at this stage, this sounds to me like a premature optimization which isn't too elegant. At this point I strongly prefer readable, maintainable and easier to debug code over optimization which isn't proven to be necessary. Thanks, Ohad. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
