| Message ID | 1389741527.24849.68.camel@joe-AO722 |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Joe Perches <joe@perches.com> Date: Tue, 14 Jan 2014 15:18:47 -0800 > Some systems can use the normally known u16 alignment of > Ethernet addresses to save some code/text bytes and cycles. > > This does not change currently emitted code on x86 by gcc 4.8. > > Signed-off-by: Joe Perches <joe@perches.com> This looks fine, in fact I'll apply it. -- 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
On Wed, 2014-01-15 at 15:39 -0800, David Miller wrote: > From: Joe Perches <joe@perches.com> > Date: Tue, 14 Jan 2014 15:18:47 -0800 > > > Some systems can use the normally known u16 alignment of > > Ethernet addresses to save some code/text bytes and cycles. > > > > This does not change currently emitted code on x86 by gcc 4.8. > > > > Signed-off-by: Joe Perches <joe@perches.com> > > This looks fine, in fact I'll apply it. OK, good. There are a couple thousand memcpy(foo, bar, ETH_ALEN) in the kernel tree that could be converted. Some will have a small performance improvement for arm and powerpc. If you want the ones for net-next net/ now (but not for batman-adv, that maybe could use a new function like ether_addr_copy_unaligned) here's a changestat. Otherwise, I'll wait for the next cycle. (done via coccinelle) net/8021q/vlan.c | 2 +- net/8021q/vlan_dev.c | 6 ++-- net/appletalk/aarp.c | 10 +++--- net/atm/lec.c | 9 ++--- net/atm/mpc.c | 2 +- net/bluetooth/bnep/core.c | 19 +++++----- net/bluetooth/bnep/netdev.c | 14 ++++---- net/bridge/br_device.c | 4 +-- net/bridge/br_fdb.c | 4 +-- net/bridge/br_multicast.c | 4 +-- net/bridge/br_netfilter.c | 2 +- net/bridge/br_stp_if.c | 10 +++--- net/bridge/netfilter/ebt_among.c | 2 +- net/bridge/netfilter/ebt_dnat.c | 2 +- net/bridge/netfilter/ebt_redirect.c | 6 ++-- net/bridge/netfilter/ebt_snat.c | 2 +- net/caif/caif_usb.c | 4 +-- net/core/netpoll.c | 4 +-- net/core/pktgen.c | 8 ++--- net/decnet/dn_dev.c | 2 +- net/decnet/dn_neigh.c | 6 ++-- net/decnet/dn_route.c | 6 ++-- net/dsa/slave.c | 2 +- net/ethernet/eth.c | 18 +++++----- net/hsr/hsr_device.c | 8 ++--- net/hsr/hsr_framereg.c | 21 +++++------ net/hsr/hsr_main.c | 4 +-- net/ipv4/netfilter/ipt_CLUSTERIP.c | 2 +- net/mac80211/agg-rx.c | 10 +++--- net/mac80211/agg-tx.c | 18 +++++----- net/mac80211/cfg.c | 34 +++++++++--------- net/mac80211/debugfs_netdev.c | 12 +++---- net/mac80211/ht.c | 16 ++++----- net/mac80211/ibss.c | 14 ++++---- net/mac80211/iface.c | 27 +++++++------- net/mac80211/mesh.c | 30 ++++++++-------- net/mac80211/mesh_hwmp.c | 32 ++++++++--------- net/mac80211/mesh_pathtbl.c | 20 +++++------ net/mac80211/mesh_plink.c | 6 ++-- net/mac80211/mesh_ps.c | 2 +- net/mac80211/mlme.c | 32 ++++++++--------- net/mac80211/rx.c | 14 ++++---- net/mac80211/spectmgmt.c | 6 ++-- net/mac80211/sta_info.c | 8 ++--- net/mac80211/tx.c | 60 +++++++++++++++---------------- net/mac80211/util.c | 22 ++++++------ net/mac80211/wpa.c | 4 +-- net/netfilter/ipset/ip_set_bitmap_ipmac.c | 6 ++-- net/openvswitch/actions.c | 4 +-- net/openvswitch/flow.c | 16 ++++----- net/openvswitch/flow_netlink.c | 14 ++++---- net/tipc/eth_media.c | 2 +- net/wireless/core.c | 2 +- net/wireless/ibss.c | 11 +++--- net/wireless/lib80211_crypt_ccmp.c | 4 +-- net/wireless/lib80211_crypt_tkip.c | 18 +++++----- net/wireless/mlme.c | 2 +- net/wireless/nl80211.c | 6 ++-- net/wireless/scan.c | 6 ++-- net/wireless/sme.c | 18 +++++----- net/wireless/util.c | 42 +++++++++++----------- net/wireless/wext-compat.c | 8 ++--- net/wireless/wext-sme.c | 5 +-- net/wireless/wext-spy.c | 8 ++--- 64 files changed, 365 insertions(+), 357 deletions(-) -- 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: Joe Perches <joe@perches.com> Date: Wed, 15 Jan 2014 16:07:58 -0800 > If you want the ones for net-next net/ now (but not > for batman-adv, that maybe could use a new function like > ether_addr_copy_unaligned) here's a changestat. > > Otherwise, I'll wait for the next cycle. This looks fine, why don't you toss it my way over the weekend as I still have some backlog to process at the moment? 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
On Wed, 2014-01-15 at 16:45 -0800, David Miller wrote: From: Joe Perches <joe@perches.com> > Date: Wed, 15 Jan 2014 16:07:58 -0800 > > > If you want the ones for net-next net/ now (but not > > for batman-adv, that maybe could use a new function like > > ether_addr_copy_unaligned) here's a changestat. > > > > Otherwise, I'll wait for the next cycle. > > This looks fine, why don't you toss it my way over the weekend as I > still have some backlog to process at the moment? I didn't get that done this weekend, so next cycle for most of net/. I don't want to introduce any breakage this late and there are possible unaligned memcpy(foo, bar, ETH_ALEN) where one or both of foo/bar are stack pointers where the alignment is hard to verify. There are also statics declared without __aligned(2) that will need updating. Maybe ether_addr_copy_unaligned should be added too. Here are the ones I could easily verify... No worries if it's this cycle or next. Joe Perches (7): 8021q: Use ether_addr_copy appletalk: Use ether_addr_copy atm: Use ether_addr_copy caif_usb: Use ether_addr_copy netpoll: Use ether_addr_copy pktgen: Use ether_addr_copy dsa: Use ether_addr_copy net/8021q/vlan.c | 2 +- net/8021q/vlan_dev.c | 6 +++--- net/appletalk/aarp.c | 12 ++++++------ net/atm/lec.c | 9 +++++---- net/atm/mpc.c | 2 +- net/caif/caif_usb.c | 4 ++-- net/core/netpoll.c | 4 ++-- net/core/pktgen.c | 8 ++++---- net/dsa/slave.c | 2 +- 9 files changed, 25 insertions(+), 24 deletions(-)
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index f344ac0..1f26c55 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -218,6 +218,28 @@ static inline void eth_hw_addr_random(struct net_device *dev) } /** + * ether_addr_copy - Copy an Ethernet address + * @dst: Pointer to a six-byte array Ethernet address destination + * @src: Pointer to a six-byte array Ethernet address source + * + * Please note: dst & src must both be aligned to u16. + */ +static inline void ether_addr_copy(u8 *dst, const u8 *src) +{ +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) + *(u32 *)dst = *(const u32 *)src; + *(u16 *)(dst + 4) = *(const u16 *)(src + 4); +#else + u16 *a = (u16 *)dst; + const u16 *b = (const u16 *)src; + + a[0] = b[0]; + a[1] = b[1]; + a[2] = b[2]; +#endif +} + +/** * eth_hw_addr_inherit - Copy dev_addr from another net_device * @dst: pointer to net_device to copy dev_addr to * @src: pointer to net_device to copy dev_addr from @@ -229,7 +251,7 @@ static inline void eth_hw_addr_inherit(struct net_device *dst, struct net_device *src) { dst->addr_assign_type = src->addr_assign_type; - memcpy(dst->dev_addr, src->dev_addr, ETH_ALEN); + ether_addr_copy(dst->dev_addr, src->dev_addr); } /**
Some systems can use the normally known u16 alignment of Ethernet addresses to save some code/text bytes and cycles. This does not change currently emitted code on x86 by gcc 4.8. Signed-off-by: Joe Perches <joe@perches.com> --- Yes, it's a trivial change, but maybe slightly useful... For instance: with netpoll.c memcpy changed to ether_addr_copy: arm old (4.6.3): memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 27e0: e4973042 ldr r3, [r7], #66 ; 0x42 27e4: e2860006 add r0, r6, #6 27e8: e3a02006 mov r2, #6 27ec: e59311e8 ldr r1, [r3, #488] ; 0x1e8 27f0: ebfffffe bl 0 <memcpy> 27f0: R_ARM_CALL memcpy memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 27f4: e1a00006 mov r0, r6 27f8: e1a01007 mov r1, r7 27fc: e3a02006 mov r2, #6 2800: ebfffffe bl 0 <memcpy> 2800: R_ARM_CALL memcpy arm new: *(u32 *)dst = *(const u32 *)src; 27dc: e5932000 ldr r2, [r3] 27e0: e5802006 str r2, [r0, #6] *(u16 *)(dst + 4) = *(const u16 *)(src + 4); 27e4: e1d330b4 ldrh r3, [r3, #4] 27e8: e1c030ba strh r3, [r0, #10] * Please note: dst & src must both be aligned to u16. */ static inline void ether_addr_copy(u8 *dst, const u8 *src) { #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) *(u32 *)dst = *(const u32 *)src; 27ec: e5953042 ldr r3, [r5, #66] ; 0x42 27f0: e5803000 str r3, [r0] *(u16 *)(dst + 4) = *(const u16 *)(src + 4); 27f4: e1d534b6 ldrh r3, [r5, #70] ; 0x46 27f8: e1c030b4 strh r3, [r0, #4] include/linux/etherdevice.h | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) -- 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