fs/select.c (from 2.4.19 but present in 2.5.x also)
asmlinkage long sys_poll(struct pollfd * ufds, unsigned int nfds, long timeout)
{
int i, j, fdcount, err;
struct pollfd **fds;
poll_table table, *wait;
int nchunks, nleft;
[ skip ]
nchunks = 0;
nleft = nfds;
while (nleft > POLLFD_PER_PAGE) { /* allocate complete PAGE_SIZE chunks
*/
fds[nchunks] = (struct pollfd *)__get_free_page(GFP_KERNEL);
if (fds[nchunks] == NULL)
goto out_fds;
nchunks++;
nleft -= POLLFD_PER_PAGE;
}
if (nleft) { /* allocate last PAGE_SIZE chunk, only nleft elements used
*/
why not -->
while (nleft >= POLLFD_PER_PAGE) {
in this case we will use only nchunks in the case that this will end up
page aligned.. the current way of using only > POLLFD_PER_PAGE will
end up with nchunks, and nleft == PAGE_SIZE / sizeof(pollfd) etc..
silly optimisation by changing > to >=, but still an optimisation.. if there
is something obviously wrong with changing > to >=, ignore me since I
probably should get more sleep.. but I dont see any problem though I havent
really looked at it too much.
attachment has 1 line (1 character) patch ;-)
--
Silvio