| Message ID | 1357572726-7059-1-git-send-email-ian.campbell@citrix.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, 2013-01-07 at 15:32 +0000, Ian Campbell wrote: > Using RX_COPY_THRESHOLD is incorrect if the SKB is actually smaller > than that. We have already accounted for this in > NETFRONT_SKB_CB(skb)->pull_to so use that instead. > > Fixes WARN_ON from skb_try_coalesce. > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> > Cc: Sander Eikelenboom <linux@eikelenboom.it> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: annie li <annie.li@oracle.com> > Cc: xen-devel@lists.xen.org > Cc: netdev@vger.kernel.org > Cc: stable@kernel.org # 3.7.x only > --- > v2: > - acount frags as a full page as recommended by Eric. Acked-by: Eric Dumazet <edumazet@google.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Ian Campbell <ian.campbell@citrix.com> Date: Mon, 7 Jan 2013 15:32:06 +0000 > Using RX_COPY_THRESHOLD is incorrect if the SKB is actually smaller > than that. We have already accounted for this in > NETFRONT_SKB_CB(skb)->pull_to so use that instead. > > Fixes WARN_ON from skb_try_coalesce. > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> > Cc: Sander Eikelenboom <linux@eikelenboom.it> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: annie li <annie.li@oracle.com> > Cc: xen-devel@lists.xen.org > Cc: netdev@vger.kernel.org > Cc: stable@kernel.org # 3.7.x only > --- > v2: > - acount frags as a full page as recommended by Eric. Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index caa0110..b518538 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -959,29 +959,10 @@ err: i = xennet_fill_frags(np, skb, &tmpq); /* - * Truesize approximates the size of true data plus - * any supervisor overheads. Adding hypervisor - * overheads has been shown to significantly reduce - * achievable bandwidth with the default receive - * buffer size. It is therefore not wise to account - * for it here. - * - * After alloc_skb(RX_COPY_THRESHOLD), truesize is set - * to RX_COPY_THRESHOLD + the supervisor - * overheads. Here, we add the size of the data pulled - * in xennet_fill_frags(). - * - * We also adjust for any unused space in the main - * data area by subtracting (RX_COPY_THRESHOLD - - * len). This is especially important with drivers - * which split incoming packets into header and data, - * using only 66 bytes of the main data area (see the - * e1000 driver for example.) On such systems, - * without this last adjustement, our achievable - * receive throughout using the standard receive - * buffer size was cut by 25%(!!!). - */ - skb->truesize += skb->data_len - RX_COPY_THRESHOLD; + * Truesize is the actual allocation size, even if the + * allocation is only partially used. + */ + skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags; skb->len += skb->data_len; if (rx->flags & XEN_NETRXF_csum_blank)
Using RX_COPY_THRESHOLD is incorrect if the SKB is actually smaller than that. We have already accounted for this in NETFRONT_SKB_CB(skb)->pull_to so use that instead. Fixes WARN_ON from skb_try_coalesce. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Sander Eikelenboom <linux@eikelenboom.it> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: annie li <annie.li@oracle.com> Cc: xen-devel@lists.xen.org Cc: netdev@vger.kernel.org Cc: stable@kernel.org # 3.7.x only --- v2: - acount frags as a full page as recommended by Eric. --- drivers/net/xen-netfront.c | 27 ++++----------------------- 1 files changed, 4 insertions(+), 23 deletions(-)