svn commit: r260501 - head/sys/dev/usb/wlan
Gleb Smirnoff
glebius at FreeBSD.org
Fri Jan 10 10:20:35 UTC 2014
Kevin,
On Fri, Jan 10, 2014 at 02:47:20AM +0000, Kevin Lo wrote:
K> Author: kevlo
K> Date: Fri Jan 10 02:47:20 2014
K> New Revision: 260501
K> URL: http://svnweb.freebsd.org/changeset/base/260501
K>
K> Log:
K> Use m_getcl() instead of MGETHDR/MCLGET macros.
K>
K> Suggested by: glebius
K>
K> Modified:
K> head/sys/dev/usb/wlan/if_rsu.c
K>
K> Modified: head/sys/dev/usb/wlan/if_rsu.c
K> ==============================================================================
K> --- head/sys/dev/usb/wlan/if_rsu.c Fri Jan 10 01:44:34 2014 (r260500)
K> +++ head/sys/dev/usb/wlan/if_rsu.c Fri Jan 10 02:47:20 2014 (r260501)
K> @@ -1145,16 +1145,9 @@ rsu_event_survey(struct rsu_softc *sc, u
K> pktlen = sizeof(*wh) + le32toh(bss->ieslen);
K> if (__predict_false(pktlen > MCLBYTES))
K> return;
K> - MGETHDR(m, M_NOWAIT, MT_DATA);
K> + m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
K> if (__predict_false(m == NULL))
K> return;
K> - if (pktlen > MHLEN) {
K> - MCLGET(m, M_NOWAIT);
K> - if (!(m->m_flags & M_EXT)) {
K> - m_free(m);
K> - return;
K> - }
K> - }
K> wh = mtod(m, struct ieee80211_frame *);
K> wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT |
K> IEEE80211_FC0_SUBTYPE_BEACON;
K> @@ -1358,19 +1351,11 @@ rsu_rx_frame(struct rsu_softc *sc, uint8
K> DPRINTFN(5, "Rx frame len=%d rate=%d infosz=%d rssi=%d\n",
K> pktlen, rate, infosz, *rssi);
K>
K> - MGETHDR(m, M_NOWAIT, MT_DATA);
K> + m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
K> if (__predict_false(m == NULL)) {
K> ifp->if_ierrors++;
K> return NULL;
K> }
K> - if (pktlen > MHLEN) {
K> - MCLGET(m, M_NOWAIT);
K> - if (__predict_false(!(m->m_flags & M_EXT))) {
K> - ifp->if_ierrors++;
K> - m_freem(m);
K> - return NULL;
K> - }
K> - }
K> /* Finalize mbuf. */
K> m->m_pkthdr.rcvif = ifp;
K> /* Hardware does Rx TCP checksum offload. */
Sorry, but the correct code would be:
if (pktlen > MHLEN)
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
else
m = m_gethdr(M_NOWAIT, MT_DATA);
if (__predict_false(m == NULL)) {
ifp->if_ierrors++;
return NULL;
}
Alternatively, you can use:
m = m_get2(pktlen, M_NOWAIT, MT_DATA, M_PKTHDR);
if (__predict_false(m == NULL)) {
ifp->if_ierrors++;
return NULL;
}
With committed code we are wasting memory for small packets.
--
Totus tuus, Glebius.
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