On Thu, 2016-09-29 at 07:49 -0700, Eric Dumazet wrote: > On Thu, Sep 29, 2016 at 7:34 AM, Paolo Abeni <pabeni@xxxxxxxxxx> wrote: > > On Thu, 2016-09-29 at 07:13 -0700, Eric Dumazet wrote: > >> On Thu, 2016-09-29 at 16:01 +0200, Paolo Abeni wrote: > >> > >> > When we reach __sk_mem_reduce_allocated() we are sure we can free the > >> > specified amount of memory, so we only need to ensure consistent > >> > sk_prot->memory_allocated updates. The current atomic operation suffices > >> > to this. > >> > >> Then why are you updating sk->sk_forward_alloc using racy operations ? > >> > >> If this is not needed or racy, do not do it. > > > > Thank you for all the feedback. > > > > The actual forward allocated memory value is: > > > > atomic_read(&up->mem_allocated) - atomic_read(&sk->sk_rmem_alloc). > > > > sk_forward_alloc is updated only to hint to the user space the forward > > allocated memory value via the diag interface. > > > > If such information is not needed we can drop the update, and > > sk_forward_alloc will always be seen as 0 even when the socket has some > > forward allocation. > > The information is needed and we want an accurate one, really. > > Think about debugging on a live server, some stuck or mad sockets ;) > > Please consider adding a proper accessor, able to deal with the UDP > peculiarities. Nice suggestion, thanks! I'll try that in v4. Perhaps is worth adding a struct proto helper for this ? I'm sorry, but I'll not be in Tokyo, so I'll probably produce some traffic on netdev in the meanwhile. Cheers, Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
