Messages in this thread |  | | | From | Andi Kleen <> | | Subject | Re: [PATCH 4/9] AF_UNIX: find the recipients for multicast messages | | Date | Mon, 22 Nov 2010 21:14:52 +0100 |
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Alban Crequy <alban.crequy@collabora.co.uk> writes:
>+static DEFINE_SPINLOCK(unix_multicast_lock);
For DBUS it's probably ok, but I suspect for other usages the global lock in the multipath fast path is going to hurt sooner or later.
> + > + /* Allocate for the set and hope the number of recipients does not > + * change while the lock is released. If it changes, we have to try > + * again... We allocate a bit more than needed, so if a _few_ members > + * are added in a multicast group meanwhile, we don't always need to > + * try again. */ > + recipient_cnt += 5; > + > + set = kmalloc(sizeof(struct sock_set) > + + sizeof(struct sock_item) * recipient_cnt, > + GFP_KERNEL);
FWIW for a large number of sockets this will likely run into memory fragmentation issues. There are various workarounds like fallback to vmalloc or use something like flex_arrays.
-Andi -- ak@linux.intel.com -- Speaking for myself only.
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