- 18 Jan, 2014 4 commits
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stephen hemminger authored
Remove function qlcnic_enable_eswitch which was defined but never used in current code. Compile tested only. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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stephen hemminger authored
Functions only used in one file should be static. Found by running make namespacecheck Compile tested only. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Florent Fourcot authored
This patch is following the commit b903d324 (ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAIT). For the same reason than tclass, we have to store the flow label in the inet_timewait_sock to provide consistency of flow label on the last ACK. Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-nextDavid S. Miller authored
John W. Linville says: ==================== Please pull this batch of updates for the 3.14 stream! For the mac80211 bits, Johannes says: "This time I have uAPSD fixes since I was working on that, hwsim improvements to make dynamic radios possible for the test suite, the evidently long-overdue channel_change_time removal and a few other small collected fix and improvements." For the iwlwifi bits, Emmanuel says: "Besides a few trivial patches, I have an important workaround for a HW issue that has kept me busy for a long time. Along with it, a fix that prevents an error from being printed. Eyal fixes our behavior against SISO APs and Ilan fixes an issue with multiple interface scenarios. Eliad fixes an error path in our init flow. We also have a few 'static analyzers' fix." For the NFC bits, Samuel says: "It includes: * A new NFC driver for Marvell's 8897, and a few NCI fixes and improvements needed to support this chipset. * An LLCP fix for how we were setting the default MIU on a p2p link. If there is no explicit MIU extension announced at connection time, we must use the default one and not the one announced at LLCP link establishement time. * A pn544 EEPROM config update. Some of the currently EEPROM configured values are overwriting the firmware ones while other should not be set by the driver itself. * Some NFC digital stack fixes and improvements. Asynchronous functions are better documented, RF technologies and CRC functions are set upon PSL_REQ reception, and a few minor bugs are fixed. * Minor and miscelaneous pn533, mei_phy and port100 fixes." For the ath bits, Kalle says: "Janusz added Kconfig option for DFS. The DFS code was there already, but after fixes to mac80211 we can now enable it. Bartosz added a runtime firmware feature flag to disable P2P. Our 10.1 firmware branch doesn't support P2P and ath10k can now disable that. He also added a limit for how many clients can connect to ath10k AP. Michal fixed WEP shared authentication, in case someone still uses it. And I added firmware debug log to help the firmware engineers." Along with that is a small batch of ath9k updates and a few other bits here and there. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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- 17 Jan, 2014 36 commits
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John W. Linville authored
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
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David S. Miller authored
Michael Dalton says: ==================== virtio-net: mergeable rx buffer size auto-tuning The virtio-net device currently uses aligned MTU-sized mergeable receive packet buffers. Network throughput for workloads with large average packet size can be improved by posting larger receive packet buffers. However, due to SKB truesize effects, posting large (e.g, PAGE_SIZE) buffers reduces the throughput of workloads that do not benefit from GRO and have no large inbound packets. This patchset introduces virtio-net mergeable buffer size auto-tuning, with buffer sizes ranging from aligned MTU-size to PAGE_SIZE. Packet buffer size is chosen based on a per-receive queue EWMA of incoming packet size. To unify mergeable receive buffer memory allocation and improve SKB frag coalescing, all mergeable buffer memory allocation is migrated to per-receive queue page frag allocators. The per-receive queue mergeable packet buffer size is exported via sysfs, and the network device sysfs layer has been extended to add support for device-specific per-receive queue sysfs attribute groups. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael Dalton authored
Add initial support for per-rx queue sysfs attributes to virtio-net. If mergeable packet buffers are enabled, adds a read-only mergeable packet buffer size sysfs attribute for each RX queue. Suggested-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael Dalton <mwdalton@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael Dalton authored
To ensure ewma_read() without a lock returns a valid but possibly out of date average, modify ewma_add() by using ACCESS_ONCE to prevent intermediate wrong values from being written to avg->internal. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Michael Dalton <mwdalton@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael Dalton authored
Extend existing support for netdevice receive queue sysfs attributes to permit a device-specific attribute group. Initial use case for this support will be to allow the virtio-net device to export per-receive queue mergeable receive buffer size. Signed-off-by: Michael Dalton <mwdalton@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael Dalton authored
Commit 2613af0e ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size, introducing a single-stream regression for benchmarks with large average packet size. There is no single optimal buffer size for all workloads. For workloads with packet size <= MTU bytes, MTU + virtio-net header-sized buffers are preferred as larger buffers reduce the TCP window due to SKB truesize. However, single-stream workloads with large average packet sizes have higher throughput if larger (e.g., PAGE_SIZE) buffers are used. This commit auto-tunes the mergeable receiver buffer packet size by choosing the packet buffer size based on an EWMA of the recent packet sizes for the receive queue. Packet buffer sizes range from MTU_SIZE + virtio-net header len to PAGE_SIZE. This improves throughput for large packet workloads, as any workload with average packet size >= PAGE_SIZE will use PAGE_SIZE buffers. These optimizations interact positively with recent commit ba275241 ("virtio-net: coalesce rx frags when possible during rx"), which coalesces adjacent RX SKB fragments in virtio_net. The coalescing optimizations benefit buffers of any size. Benchmarks taken from an average of 5 netperf 30-second TCP_STREAM runs between two QEMU VMs on a single physical machine. Each VM has two VCPUs with all offloads & vhost enabled. All VMs and vhost threads run in a single 4 CPU cgroup cpuset, using cgroups to ensure that other processes in the system will not be scheduled on the benchmark CPUs. Trunk includes SKB rx frag coalescing. net-next w/ virtio_net before 2613af0e (PAGE_SIZE bufs): 14642.85Gb/s net-next (MTU-size bufs): 13170.01Gb/s net-next + auto-tune: 14555.94Gb/s Jason Wang also reported a throughput increase on mlx4 from 22Gb/s using MTU-sized buffers to about 26Gb/s using auto-tuning. Signed-off-by: Michael Dalton <mwdalton@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael Dalton authored
The virtio-net driver currently uses netdev_alloc_frag() for GFP_ATOMIC mergeable rx buffer allocations. This commit migrates virtio-net to use per-receive queue page frags for GFP_ATOMIC allocation. This change unifies mergeable rx buffer memory allocation, which now will use skb_refill_frag() for both atomic and GFP-WAIT buffer allocations. To address fragmentation concerns, if after buffer allocation there is too little space left in the page frag to allocate a subsequent buffer, the remaining space is added to the current allocated buffer so that the remaining space can be used to store packet data. Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael Dalton <mwdalton@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael Dalton authored
skb_page_frag_refill currently permits only order-0 page allocs unless GFP_WAIT is used. Change skb_page_frag_refill to attempt higher-order page allocations whether or not GFP_WAIT is used. If memory cannot be allocated, the allocator will fall back to successively smaller page allocs (down to order-0 page allocs). This change brings skb_page_frag_refill in line with the existing page allocation strategy employed by netdev_alloc_frag, which attempts higher-order page allocations whether or not GFP_WAIT is set, falling back to successively lower-order page allocations on failure. Part of migration of virtio-net to per-receive queue page frag allocators. Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Michael Dalton <mwdalton@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Wei Yongjun authored
The error code was not set if change indev fail, so the error condition wasn't reflected in the return value. Fix to return a negative error code from this error handling case instead of 0. Fixes: 2519a602 ('net_sched: optimize tcf_match_indev()') Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored
Ying Xue says: ==================== tipc: align TIPC behaviours of waiting for events with other stacks Comparing the current implementations of waiting for events in TIPC socket layer with other stacks, TIPC's behaviour is very different because wait_event_interruptible_timeout()/wait_event_interruptible() are always used by TIPC to wait for events while relevant socket or port variables are fed to them as their arguments. As socket lock has to be released temporarily before the two routines of waiting for events are called, their arguments associated with socket or port structures are out of socket lock protection. This might cause serious issues where the process of calling socket syscall such as sendsmg(), connect(), accept(), and recvmsg(), cannot be waken up at all even if proper event arrives or improperly be woken up although the condition of waking up the process is not satisfied in practice. Therefore, aligning its behaviours with similar functions implemented in other stacks, for instance, sk_stream_wait_connect() and inet_csk_wait_for_connect() etc, can avoid above risks for us. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Ying Xue authored
Standardize the behaviour of waiting for events in TIPC recvmsg() so that all variables of socket or port structures are protected within socket lock, allowing the process of calling recvmsg() to be woken up at appropriate time. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Ying Xue authored
Standardize the behaviour of waiting for events in TIPC send_packet() so that all variables of socket or port structures are protected within socket lock, allowing the process of calling sendmsg() to be woken up at appropriate time. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Ying Xue authored
Comparing the behaviour of how to wait for events in TIPC sendmsg() with other stacks, the TIPC implementation might be perceived as different, and sometimes even incorrect. For instance, sk_sleep() and tport->congested variables associated with socket are exposed without socket lock protection while wait_event_interruptible_timeout() accesses them. So standardizing it with similar implementation in other stacks can help us correct these errors which the process of calling sendmsg() cannot be woken up event if an expected event arrive at socket or improperly woken up although the wake condition doesn't match. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Ying Xue authored
Comparing the behaviour of how to wait for events in TIPC accept() with other stacks, the TIPC implementation might be perceived as different, and sometimes even incorrect. As sk_sleep() and sk->sk_receive_queue variables associated with socket are not protected by socket lock, the process of calling accept() may be woken up improperly or sometimes cannot be woken up at all. After standardizing it with inet_csk_wait_for_connect routine, we can get benefits including: avoiding 'thundering herd' phenomenon, adding a timeout mechanism for accept(), coping with a pending signal, and having sk_sleep() and sk->sk_receive_queue being always protected within socket lock scope and so on. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Ying Xue authored
Comparing the behaviour of how to wait for events in TIPC connect() with other stacks, the TIPC implementation might be perceived as different, and sometimes even incorrect. For instance, as both sock->state and sk_sleep() are directly fed to wait_event_interruptible_timeout() as its arguments, and socket lock has to be released before we call wait_event_interruptible_timeout(), the two variables associated with socket are exposed out of socket lock protection, thereby probably getting stale values so that the process of calling connect() cannot be woken up exactly even if correct event arrives or it is woken up improperly even if the wake condition is not satisfied in practice. Therefore, standardizing its behaviour with sk_stream_wait_connect routine can avoid these risks. Additionally the implementation of connect routine is simplified as a whole, allowing it to return correct values in all different cases. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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wangweidong authored
When go the right path, the status is 0, no need to assign it again. So just remove the assignment. Signed-off-by: Wang Weidong <wangweidong1@huawei.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Jason Wang authored
It looks like there's no need for those two fields: - Unless there's a failure for the first refill try, rq->max should be always equal to the vring size. - rq->num is only used to determine the condition that we need to do the refill, we could check vq->num_free instead. - rq->num was required to be increased or decreased explicitly after each get/put which results a bad API. So this patch removes them both to make the code simpler. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Lad, Prabhakar authored
This patch fixes following sparse warning davinci_mdio.c:85:27: warning: symbol 'default_pdata' was not declared. Should it be static? Also makes the default_pdata as a constant. Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Acked-by: Mugunthan V N <mugunthanvnm@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Veaceslav Falico authored
Currently, if a slave's name change, we just pass it by. However, if the slave is a current primary_slave, then we end up with using a slave, whose name != params.primary, for primary_slave. And vice-versa, if we don't have a primary_slave but have params.primary set - we will not detected a new primary_slave. Fix this by catching the NETDEV_CHANGENAME event and setting primary_slave accordingly. Also, if the primary_slave was changed, issue a reselection of the active slave, cause the priorities have changed. Reported-by: Ding Tianhong <dingtianhong@huawei.com> CC: Ding Tianhong <dingtianhong@huawei.com> CC: Jay Vosburgh <fubar@us.ibm.com> CC: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: Veaceslav Falico <vfalico@redhat.com> Acked-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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WANG Cong authored
In tcf_register_action() we check either ->type or ->kind to see if there is an existing action registered, but ipt action registers two actions with same type but different kinds. They should have different types too. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.open-mesh.org/linux-mergeDavid S. Miller authored
Included change: - properly format already existing kerneldoc Signed-off-by: David S. Miller <davem@davemloft.net>
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WANG Cong authored
Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Shannon Nelson authored
Refinements to cloud support in the Firmware API. Signed-off-by: Shannon Nelson <shannon.nelson@intel.com> Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com> Signed-off-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Shannon Nelson authored
Check that the descriptors were allocated before trying to dump them to the logfile. While we're there, de-trick-ify the code so as to be easier to read and not abusing the types and unions. Change-ID: I22898f4b22cecda3582d4d9e4018da9cd540f177 Signed-off-by: Shannon Nelson <shannon.nelson@intel.com> Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com> Signed-off-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Veaceslav Falico authored
Now it catches the NETDEV_CHANGEMTU notification, which is signaled after the actual change happened on the device, and returns NOTIFY_BAD, so that the change on the device is reverted. This might be quite costly and messy, so use the new NETDEV_PRECHANGEMTU to catch the MTU change before the actual change happens and signal that it's forbidden to do it. CC: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Veaceslav Falico <vfalico@redhat.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
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Veaceslav Falico authored
Currently, if a device changes its mtu, first the change happens (invloving all the side effects), and after that the NETDEV_CHANGEMTU is sent so that other devices can catch up with the new mtu. However, if they return NOTIFY_BAD, then the change is reverted and error returned. This is a really long and costy operation (sometimes). To fix this, add NETDEV_PRECHANGEMTU notification which is called prior to any change actually happening, and if any callee returns NOTIFY_BAD - the change is aborted. This way we're skipping all the playing with apply/revert the mtu. CC: "David S. Miller" <davem@davemloft.net> CC: Jiri Pirko <jiri@resnulli.us> CC: Eric Dumazet <edumazet@google.com> CC: Nicolas Dichtel <nicolas.dichtel@6wind.com> CC: Cong Wang <amwang@redhat.com> Signed-off-by: Veaceslav Falico <vfalico@redhat.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
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Florian Fainelli authored
Ever since this driver was merged the following code was included: if (skb->len < MISR) skb->len = MISR; MISR is defined to 0x3C which is also equivalent to ETH_ZLEN, but use ETH_ZLEN directly which is exactly what we want to be checking for. Reported-by: Marc Volovic <marcv@ezchip.com> Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Florian Fainelli authored
On newer and faster machines (Vortex X86DX) using the r6040 driver, it was noticed that the driver was returning an error during probing traced down to being the MDIO bus probing and the inability to complete a MDIO read operation in time. It turns out that the MDIO operations on these faster machines usually complete after ~2140 iterations which is bigger than 2048 (MAC_DEF_TIMEOUT) and results in spurious timeouts depending on the system load. Update r6040_phy_read() and r6040_phy_write() to include a 1 micro second delay in each busy-looping iteration of the loop which is a much safer operation than incrementing MAC_DEF_TIMEOUT. Reported-by: Nils Koehler <nils.koehler@ibt-interfaces.de> Reported-by: Daniel Goertzen <daniel.goertzen@gmail.com> Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Paul Durrant authored
This patch adds support for IPv6 checksum offload and GSO when those features are available in the backend. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Tom Herbert authored
When initializing a gro_list for a packet, first check the rxhash of the incoming skb against that of the skb's in the list. This should be a very strong inidicator of whether the flow is going to be matched, and potentially allows a lot of other checks to be short circuited. Use skb_hash_raw so that we don't force the hash to be calculated. Tested by running netperf 200 TCP_STREAMs between two machines with GRO, HW rxhash, and 1G. Saw no performance degration, slight reduction of time in dev_gro_receive. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Tom Herbert authored
Function to just return skb->rxhash without checking to see if it needs to be recomputed. Signed-off-by: Tom Herbert <therbert@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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stephen hemminger authored
Remove unused function vxge_hw_vpath_vid_get Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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stephen hemminger authored
Use 'make namespacecheck' to code that could be declared static. After that remove code that is not being used. Compile tested only. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Barry Song authored
recently, dm9000 codes have many checkpatch errors and warnings: WARNING: please, no space before tabs 3: FILE: dm9000.c:3: + * ^ICopyright (C) 1997 Sten Wang$ WARNING: please, no space before tabs 5: FILE: dm9000.c:5: + * ^IThis program is free software; you can redistribute it and/or$ WARNING: please, no space before tabs 6: FILE: dm9000.c:6: + * ^Imodify it under the terms of the GNU General Public License$ WARNING: please, no space before tabs 7: FILE: dm9000.c:7: + * ^Ias published by the Free Software Foundation; either version 2$ WARNING: please, no space before tabs 8: FILE: dm9000.c:8: + * ^Iof the License, or (at your option) any later version.$ WARNING: please, no space before tabs 10: FILE: dm9000.c:10: + * ^IThis program is distributed in the hope that it will be useful,$ WARNING: please, no space before tabs 11: FILE: dm9000.c:11: + * ^Ibut WITHOUT ANY WARRANTY; without even the implied warranty of$ WARNING: please, no space before tabs 12: FILE: dm9000.c:12: + * ^IMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the$ WARNING: please, no space before tabs 13: FILE: dm9000.c:13: + * ^IGNU General Public License for more details.$ WARNING: do not add new typedefs 97: FILE: dm9000.c:97: +typedef struct board_info { ERROR: spaces prohibited around that ':' (ctx:WxV) 113: FILE: dm9000.c:113: + unsigned int in_suspend :1; ^ ERROR: spaces prohibited around that ':' (ctx:WxV) 114: FILE: dm9000.c:114: + unsigned int wake_supported :1; ^ This patch fixes important errors in it. Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Daniel Borkmann authored
In PF_PACKET's packet mmap(), we can avoid using one atomic_inc() and one atomic_dec() call in skb destructor and use a percpu reference count instead in order to determine if packets are still pending to be sent out. Micro-benchmark with [1] that has been slightly modified (that is, protcol = 0 in socket(2) and bind(2)), example on a rather crappy testing machine; I expect it to scale and have even better results on bigger machines: ./packet_mm_tx -s7000 -m7200 -z700000 em1, avg over 2500 runs: With patch: 4,022,015 cyc Without patch: 4,812,994 cyc time ./packet_mm_tx -s64 -c10000000 em1 > /dev/null, stable: With patch: real 1m32.241s user 0m0.287s sys 1m29.316s Without patch: real 1m38.386s user 0m0.265s sys 1m35.572s In function tpacket_snd(), it is okay to use packet_read_pending() since in fast-path we short-circuit the condition already with ph != NULL, since we have next frames to process. In case we have MSG_DONTWAIT, we also do not execute this path as need_wait is false here anyway, and in case of _no_ MSG_DONTWAIT flag, it is okay to call a packet_read_pending(), because when we ever reach that path, we're done processing outgoing frames anyway and only look if there are skbs still outstanding to be orphaned. We can stay lockless in this percpu counter since it's acceptable when we reach this path for the sum to be imprecise first, but we'll level out at 0 after all pending frames have reached the skb destructor eventually through tx reclaim. When people pin a tx process to particular CPUs, we expect overflows to happen in the reference counter as on one CPU we expect heavy increase; and distributed through ksoftirqd on all CPUs a decrease, for example. As David Laight points out, since the C language doesn't define the result of signed int overflow (i.e. rather than wrap, it is allowed to saturate as a possible outcome), we have to use unsigned int as reference count. The sum over all CPUs when tx is complete will result in 0 again. The BUG_ON() in tpacket_destruct_skb() we can remove as well. It can _only_ be set from inside tpacket_snd() path and we made sure to increase tx_ring.pending in any case before we called po->xmit(skb). So testing for tx_ring.pending == 0 is not too useful. Instead, it would rather have been useful to test if lower layers didn't orphan the skb so that we're missing ring slots being put back to TP_STATUS_AVAILABLE. But such a bug will be caught in user space already as we end up realizing that we do not have any TP_STATUS_AVAILABLE slots left anymore. Therefore, we're all set. Btw, in case of RX_RING path, we do not make use of the pending member, therefore we also don't need to use up any percpu memory here. Also note that __alloc_percpu() already returns a zero-filled percpu area, so initialization is done already. [1] http://wiki.ipxwarzone.com/index.php5?title=Linux_packet_mmapSigned-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Daniel Borkmann authored
In tpacket_snd(), when we've discovered a first frame that is not in status TP_STATUS_SEND_REQUEST, and return a NULL buffer, we exit the send routine in case of MSG_DONTWAIT, since we've finished traversing the mmaped send ring buffer and don't care about pending frames. While doing so, we still unconditionally call an expensive schedule() in the packet_current_frame() "error" path, which is unnecessary in this case since it's enough to just quit the function. Also, in case MSG_DONTWAIT is not set, we should rather test for need_resched() first and do schedule() only if necessary since meanwhile pending frames could already have finished processing and called skb destructor. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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