Re: [PATCH] vhost: allow for many vhost user ports
From: Yuanhan Liu <hidden>
Date: 2016-12-06 06:55:50
On Thu, Dec 01, 2016 at 04:26:50PM +0100, Jan Wickbom wrote:
Currently select() is used to monitor file descriptors for vhostuser ports. This limits the number of ports possible to create since the fd number is used as index in the fd_set and we have seen fds > 1023.
Yeah, it's a known issue for a while. Thanks for making a patch to fix that!
This patch changes select() to poll(). This way we can keep an packed (pollfd) array for the fds, e.g. as many fds as the size of the array. Also see: http://dpdk.org/ml/archives/dev/2016-April/037024.html
...
+/** + * Adjusts the highest index populated in the array of fds
This function only shrinks (but not extends) the fdset array, so why not naming it to something like "fdset_shrink".
+ * @return + * Index of highest position populated + 1.
I think it's clearer to say "The new size of fdset".
quoted hunk ↗ jump to hunk
@@ -189,7 +206,7 @@ pfdset->fd[i].fd = -1; pfdset->fd[i].rcb = pfdset->fd[i].wcb = NULL; pfdset->fd[i].dat = NULL; - pfdset->num--; + (void) fdset_adjust_num(pfdset);
Unncessary cast.
quoted hunk ↗ jump to hunk
i = -1; } pthread_mutex_unlock(&pfdset->fd_mutex);@@ -211,12 +228,12 @@ pfdset->fd[index].fd = -1; pfdset->fd[index].rcb = pfdset->fd[index].wcb = NULL; - pfdset->fd[index].dat = NULL; - pfdset->num--; + (void) fdset_adjust_num(pfdset); pthread_mutex_unlock(&pfdset->fd_mutex); } + /** * This functions runs in infinite blocking loop until there is no fd in * pfdset. It calls corresponding r/w handler if there is event on the fd.@@ -229,44 +246,48 @@ void fdset_event_dispatch(struct fdset *pfdset) { - fd_set rfds, wfds; - int i, maxfds; + int i; struct fdentry *pfdentry; - int num = MAX_FDS; + int numfds; fd_cb rcb, wcb; void *dat; int fd; int remove1, remove2; int ret; + int handled; if (pfdset == NULL) return; + struct pollfd * const rwfds = + rte_malloc("struct pollfd", MAX_FDS * sizeof(*rwfds), 0);
There is neither a NULL check, nor a free after the usage. Since it's a fixed size at compile time (MAX_FDS), you might want to define a static array for that. --yliu