On Mon, 26 Feb 2007, Ingo Molnar wrote: > > * Ingo Molnar <[EMAIL PROTECTED]> wrote: > > > please also try evserver_epoll_threadlet.c that i've attached below - > > it uses epoll as the main event mechanism but does threadlets for > > request handling. > > find updated code below - your evserver_epoll.c spuriously missed event > edges - so i changed it back to level-triggered. While that is not as > fast as edge-triggered, it does not result in spurious hangs and > workflow 'hickups' during the test. > > Could this be the reason why in your testing kevents outperformed epoll?
This is how I handle a read (write/accept/connect, same thing) inside coronet (coroutine+epoll async library - http://www.xmailserver.org/coronet-lib.html ). static int conet_read_ll(struct sk_conn *conn, char *buf, int nbyte) { int n; while ((n = read(conn->sfd, buf, nbyte)) < 0) { if (errno == EINTR) continue; if (errno != EAGAIN && errno != EWOULDBLOCK) return -1; if (!(conn->events & EPOLLIN)) { conn->events = EPOLLIN; if (conet_mod_conn(conn, conn->events) < 0) return -1; } if (conet_yield(conn) < 0) return -1; } return n; } I use EPOLLET and, you don't change the interest set until you actually get an EAGAIN. *Many* read/write mode changes in the usage will simply happen w/out an epoll_ctl() needed. The conet_mod_conn() function does the actual epoll_ctl() and add EPOLLET to the specified event set. The conet_yield() function end up calling the libpcl's co_resume(), that is basically a switch-to-next-coroutine-until-fd-becomes-ready (maps directly to a swapcontext). That cuts 50+% of the epoll_ctl(EPOLL_CTL_MOD). - Davide - 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/
