> -----Original Message----- > From: Jan Beulich [mailto:jbeul...@suse.com] > Sent: 13 November 2017 10:50 > To: Paul Durrant <paul.durr...@citrix.com> > Cc: Wei Liu <wei.l...@citrix.com>; xen-de...@lists.xenproject.org; 'Joao > Martins' <joao.m.mart...@oracle.com>; netdev@vger.kernel.org > Subject: Re: [Xen-devel] [PATCH net-next v1] xen-netback: make copy batch > size configurable > > >>> On 13.11.17 at 11:33, <paul.durr...@citrix.com> wrote: > >> From: Joao Martins [mailto:joao.m.mart...@oracle.com] > >> Sent: 10 November 2017 19:35 > >> --- a/drivers/net/xen-netback/netback.c > >> +++ b/drivers/net/xen-netback/netback.c > >> @@ -96,6 +96,11 @@ unsigned int xenvif_hash_cache_size = > >> XENVIF_HASH_CACHE_SIZE_DEFAULT; > >> module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, > >> 0644); > > Isn't the "owner-write" permission here ... > > >> --- a/drivers/net/xen-netback/rx.c > >> +++ b/drivers/net/xen-netback/rx.c > >> @@ -168,11 +168,14 @@ static void xenvif_rx_copy_add(struct > >> xenvif_queue *queue, > >> struct xen_netif_rx_request *req, > >> unsigned int offset, void *data, size_t len) > >> { > >> + unsigned int batch_size; > >> struct gnttab_copy *op; > >> struct page *page; > >> struct xen_page_foreign *foreign; > >> > >> - if (queue->rx_copy.num == COPY_BATCH_SIZE) > >> + batch_size = min(xenvif_copy_batch_size, queue->rx_copy.size); > > > > Surely queue->rx_copy.size and xenvif_copy_batch_size are always > identical? > > Why do you need this statement (and hence stack variable)? > > ... the answer to your question?
Yes, I guess it could be... but since there's no re-alloc code for the arrays I wonder whether the intention was to make this dynamic or not. Paul > > Jan
