build_skb() should look at the page pfmemalloc status.
If set, this means page allocator allocated this page in the
expectation it would help to free other pages. Networking
stack can do that only if skb->pfmemalloc is also set.
Also, we must refrain using high order pages from the pfmemalloc
reserve, so __page_frag_refill() must also use __GFP_NOMEMALLOC for
them. Under memory pressure, using order-0 pages is probably the best
strategy.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Wed, Apr 15, 2015 at 05:41:26PM +0200, Nicolas Dichtel wrote:
> Le 15/04/2015 15:57, Herbert Xu a écrit :
> >On Wed, Apr 15, 2015 at 06:22:29PM +0800, Herbert Xu wrote:
> [snip]
> >Subject: skbuff: Do not scrub skb mark within the same name space
> >
> >The commit ea23192e8e ("tunnels:
> Maybe add a Fixes tag?
> Fixes: ea23192e8e ("tunnels: harmonize cleanup done on skb on rx path")
>
> >harmonize cleanup done on skb on rx path") broke anyone trying to
> >use netfilter marking across IPv4 tunnels. While most of the
> >fields that are cleared by skb_scrub_packet don't matter, the
> >netfilter mark must be preserved.
> >
> >This patch rearranges skb_scurb_packet to preserve the mark field.
> nit: s/scurb/scrub
>
> Else it's fine for me.
Sure.
PS I used the wrong email for James the first time around. So
let me repeat the question here. Should secmark be preserved
or cleared across tunnels within the same name space? In fact,
do our security models even support name spaces?
---8<---
The commit ea23192e8e ("tunnels:
harmonize cleanup done on skb on rx path") broke anyone trying to
use netfilter marking across IPv4 tunnels. While most of the
fields that are cleared by skb_scrub_packet don't matter, the
netfilter mark must be preserved.
This patch rearranges skb_scrub_packet to preserve the mark field.
Fixes: ea23192e8e ("tunnels: harmonize cleanup done on skb on rx path")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch reverts commit b8fb4e0648
because the secmark must be preserved even when a packet crosses
namespace boundaries. The reason is that security labels apply to
the system as a whole and is not per-namespace.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/emulex/benet/be_main.c
net/core/sysctl_net_core.c
net/ipv4/inet_diag.c
The be_main.c conflict resolution was really tricky. The conflict
hunks generated by GIT were very unhelpful, to say the least. It
split functions in half and moved them around, when the real actual
conflict only existed solely inside of one function, that being
be_map_pci_bars().
So instead, to resolve this, I checked out be_main.c from the top
of net-next, then I applied the be_main.c changes from 'net' since
the last time I merged. And this worked beautifully.
The inet_diag.c and sysctl_net_core.c conflicts were simple
overlapping changes, and were easily to resolve.
Signed-off-by: David S. Miller <davem@davemloft.net>
Test that sk != NULL before reading sk->sk_tsflags.
Fixes: 49ca0d8bfa ("net-timestamp: no-payload option")
Reported-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
John reported that my previous commit added a regression
on his router.
This is because sender_cpu & napi_id share a common location,
so get_xps_queue() can see garbage and perform an out of bound access.
We need to make sure sender_cpu is cleared before doing the transmit,
otherwise any NIC busy poll enabled (skb_mark_napi_id()) can trigger
this bug.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: John <jw@nuclearfallout.net>
Bisected-by: John <jw@nuclearfallout.net>
Fixes: 2bd82484bb ("xps: fix xps for stacked devices")
Signed-off-by: David S. Miller <davem@davemloft.net>
Some drivers use copybreak to copy tiny frames into smaller skb,
and this smaller skb might not have skb->head_frag set for various
reasons.
skb_gro_receive() currently doesn't allow to aggregate the smaller skb
into the previous GRO packet if this GRO packet has at least 2 MSS in
it.
Following workload easily demonstrates the problem.
netperf -t TCP_RR -H target -- -r 3000,3000
(tcpdump shows one GRO packet with 2 MSS, plus one additional packet of
104 bytes that should have been appended.)
It turns out that we can remove code from skb_gro_receive(), because
commit 8a29111c7c ("net: gro: allow to build full sized skb") and its
followups removed the assumption that a GRO packet with a frag_list had
to have an empty head.
Removing this code allows the aggregation of the last (incomplete) frame
in some RPC workloads. Note that tcp_gro_receive() already takes care of
forcing a flush if necessary, including this case.
If we want to avoid using frag_list in the first place (in forwarding
workloads for example, as the outgoing NIC is generally not able to cope
with skbs having a frag_list), we need to address this separately.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/rocker/rocker.c
The rocker commit was two overlapping changes, one to rename
the ->vport member to ->pport, and another making the bitmask
expression use '1ULL' instead of plain '1'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Although it is clear that textsearch state is intentionally passed to
skb_find_text() as uninitialized argument, it was never used by the
callers. Therefore, we can simplify skb_find_text() by making it
local variable.
Signed-off-by: Bojan Prtvar <prtvar.b@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Non NAPI drivers can call skb_tstamp_tx() and then sock_queue_err_skb()
from hard IRQ context.
Therefore, sock_dequeue_err_skb() needs to block hard irq or
corruptions or hangs can happen.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 364a9e9324 ("sock: deduplicate errqueue dequeue")
Fixes: cb820f8e4b ("net: Provide a generic socket error queue delivery method for Tx time stamps.")
Signed-off-by: David S. Miller <davem@davemloft.net>
A typical qdisc setup is the following :
bond0 : bonding device, using HTB hierarchy
eth1/eth2 : slaves, multiqueue NIC, using MQ + FQ qdisc
XPS allows to spread packets on specific tx queues, based on the cpu
doing the send.
Problem is that dequeues from bond0 qdisc can happen on random cpus,
due to the fact that qdisc_run() can dequeue a batch of packets.
CPUA -> queue packet P1 on bond0 qdisc, P1->ooo_okay=1
CPUA -> queue packet P2 on bond0 qdisc, P2->ooo_okay=0
CPUB -> dequeue packet P1 from bond0
enqueue packet on eth1/eth2
CPUC -> dequeue packet P2 from bond0
enqueue packet on eth1/eth2 using sk cache (ooo_okay is 0)
get_xps_queue() then might select wrong queue for P1, since current cpu
might be different than CPUA.
P2 might be sent on the old queue (stored in sk->sk_tx_queue_mapping),
if CPUC runs a bit faster (or CPUB spins a bit on qdisc lock)
Effect of this bug is TCP reorders, and more generally not optimal
TX queue placement. (A victim bulk flow can be migrated to the wrong TX
queue for a while)
To fix this, we have to record sender cpu number the first time
dev_queue_xmit() is called for one tx skb.
We can union napi_id (used on receive path) and sender_cpu,
granted we clear sender_cpu in skb_scrub_packet() (credit to Willem for
this union idea)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tx timestamps are looped onto the error queue on top of an skb. This
mechanism leaks packet headers to processes unless the no-payload
options SOF_TIMESTAMPING_OPT_TSONLY is set.
Add a sysctl that optionally drops looped timestamp with data. This
only affects processes without CAP_NET_RAW.
The policy is checked when timestamps are generated in the stack.
It is possible for timestamps with data to be reported after the
sysctl is set, if these were queued internally earlier.
No vulnerability is immediately known that exploits knowledge
gleaned from packet headers, but it may still be preferable to allow
administrators to lock down this path at the cost of possible
breakage of legacy applications.
Signed-off-by: Willem de Bruijn <willemb@google.com>
----
Changes
(v1 -> v2)
- test socket CAP_NET_RAW instead of capable(CAP_NET_RAW)
(rfc -> v1)
- document the sysctl in Documentation/sysctl/net.txt
- fix access control race: read .._OPT_TSONLY only once,
use same value for permission check and skb generation.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add timestamping option SOF_TIMESTAMPING_OPT_TSONLY. For transmit
timestamps, this loops timestamps on top of empty packets.
Doing so reduces the pressure on SO_RCVBUF. Payload inspection and
cmsg reception (aside from timestamps) are no longer possible. This
works together with a follow on patch that allows administrators to
only allow tx timestamping if it does not loop payload or metadata.
Signed-off-by: Willem de Bruijn <willemb@google.com>
----
Changes (rfc -> v1)
- add documentation
- remove unnecessary skb->len test (thanks to Richard Cochran)
Signed-off-by: David S. Miller <davem@davemloft.net>
The same macros are used for rx as well. So rename it.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Not needed, only four cases:
- kfree_skb (or one of its aliases).
Don't need to zero, memory will be freed.
- kfree_skb_partial and head was stolen: memory will be freed.
- skb_morph: The skb header fields (including tc ones) will be
copied over from the 'to-be-morphed' skb right after
skb_release_head_state returns.
- skb_segment: Same as before, all the skb header
fields are copied over from the original skb right away.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_scrub_packet() is called when a packet switches between a context
such as between underlay and overlay, between namespaces, or between
L3 subnets.
While we already scrub the packet mark, connection tracking entry,
and cached destination, the security mark/context is left intact.
It seems wrong to inherit the security context of a packet when going
from overlay to underlay or across forwarding paths.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change pulls the core functionality out of __netdev_alloc_skb and
places them in a new function named __alloc_rx_skb. The reason for doing
this is to make these bits accessible to a new function __napi_alloc_skb.
In addition __alloc_rx_skb now has a new flags value that is used to
determine which page frag pool to allocate from. If the SKB_ALLOC_NAPI
flag is set then the NAPI pool is used. The advantage of this is that we
do not have to use local_irq_save/restore when accessing the NAPI pool from
NAPI context.
In my test setup I saw at least 11ns of savings using the napi_alloc_skb
function versus the netdev_alloc_skb function, most of this being due to
the fact that we didn't have to call local_irq_save/restore.
The main use case for napi_alloc_skb would be for things such as copybreak
or page fragment based receive paths where an skb is allocated after the
data has been received instead of before.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch splits the netdev_alloc_frag function up so that it can be used
on one of two page frag pools instead of being fixed on the
netdev_alloc_cache. By doing this we can add a NAPI specific function
__napi_alloc_frag that accesses a pool that is only used from softirq
context. The advantage to this is that we do not need to call
local_irq_save/restore which can be a significant savings.
I also took the opportunity to refactor the core bits that were placed in
__alloc_page_frag. First I updated the allocation to do either a 32K
allocation or an order 0 page. This is based on the changes in commmit
d9b2938aa where it was found that latencies could be reduced in case of
failures. Then I also rewrote the logic to work from the end of the page to
the start. By doing this the size value doesn't have to be used unless we
have run out of space for page fragments. Finally I cleaned up the atomic
bits so that we just do an atomic_sub_and_test and if that returns true then
we set the page->_count via an atomic_set. This way we can remove the extra
conditional for the atomic_read since it would have led to an atomic_inc in
the case of success anyway.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit ce1a4ea3f1 ("net: avoid one atomic operation in skb_clone()")
took the wrong way to save one atomic operation.
It is actually possible to avoid two atomic operations, if we
do not change skb->fclone values, and only rely on clone_ref
content to signal if the clone is available or not.
skb_clone() can simply use the fast clone if clone_ref is 1.
kfree_skbmem() can avoid the atomic_dec_and_test() if clone_ref is 1.
Note that because we usually free the clone before the original skb,
this particular attempt is only done for the original skb to have better
branch prediction.
SKB_FCLONE_FREE is removed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Chris Mason <clm@fb.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ieee802154/fakehard.c
A bug fix went into 'net' for ieee802154/fakehard.c, which is removed
in 'net-next'.
Add build fix into the merge from Stephen Rothwell in openvswitch, the
logging macros take a new initial 'log' argument, a new call was added
in 'net' so when we merge that in here we have to explicitly add the
new 'log' arg to it else the build fails.
Signed-off-by: David S. Miller <davem@davemloft.net>
Not sure what I was thinking, but doing anything after
releasing a refcount is suicidal or/and embarrassing.
By the time we set skb->fclone to SKB_FCLONE_FREE, another cpu
could have released last reference and freed whole skb.
We potentially corrupt memory or trap if CONFIG_DEBUG_PAGEALLOC is set.
Reported-by: Chris Mason <clm@fb.com>
Fixes: ce1a4ea3f1 ("net: avoid one atomic operation in skb_clone()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
So it can be used from out of openvswitch code.
Did couple of cosmetic changes on the way, namely variable naming and
adding support for 8021AD proto.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
note that skb_make_writable already exists in net/netfilter/core.c
but does something slightly different.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new GSO type, SKB_GSO_TUNNEL_REMCSUM, which indicates remote
checksum offload being done (in this case inner checksum must not
be offloaded to the NIC).
Added logic in __skb_udp_tunnel_segment to handle remote checksum
offload case.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch generalizes commit d6a4a10411 ("tcp: GSO should be TSQ
friendly") to protocols using skb_set_owner_w()
TCP uses its own destructor (tcp_wfree) and needs a more complex scheme
as explained in commit 6ff50cd555 ("tcp: gso: do not generate out of
order packets")
This allows UDP sockets using UFO to get proper backpressure,
thus avoiding qdisc drops and excessive cpu usage.
Here are performance test results (macvlan on vlan):
- Before
# netperf -t UDP_STREAM ...
Socket Message Elapsed Messages
Size Size Time Okay Errors Throughput
bytes bytes secs # # 10^6bits/sec
212992 65507 60.00 144096 1224195 1258.56
212992 60.00 51 0.45
Average: CPU %user %nice %system %iowait %steal %idle
Average: all 0.23 0.00 25.26 0.08 0.00 74.43
- After
# netperf -t UDP_STREAM ...
Socket Message Elapsed Messages
Size Size Time Okay Errors Throughput
bytes bytes secs # # 10^6bits/sec
212992 65507 60.00 109593 0 957.20
212992 60.00 109593 957.20
Average: CPU %user %nice %system %iowait %steal %idle
Average: all 0.18 0.00 8.38 0.02 0.00 91.43
[edumazet] Rewrote patch and changelog.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
if ->encapsulation is set we have to use inner_tcp_hdrlen and add the
size of the inner network headers too.
This is 'mostly harmless'; tbf might send skb that is slightly over
quota or drop skb even if it would have fit.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull percpu consistent-ops changes from Tejun Heo:
"Way back, before the current percpu allocator was implemented, static
and dynamic percpu memory areas were allocated and handled separately
and had their own accessors. The distinction has been gone for many
years now; however, the now duplicate two sets of accessors remained
with the pointer based ones - this_cpu_*() - evolving various other
operations over time. During the process, we also accumulated other
inconsistent operations.
This pull request contains Christoph's patches to clean up the
duplicate accessor situation. __get_cpu_var() uses are replaced with
with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().
Unfortunately, the former sometimes is tricky thanks to C being a bit
messy with the distinction between lvalues and pointers, which led to
a rather ugly solution for cpumask_var_t involving the introduction of
this_cpu_cpumask_var_ptr().
This converts most of the uses but not all. Christoph will follow up
with the remaining conversions in this merge window and hopefully
remove the obsolete accessors"
* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
irqchip: Properly fetch the per cpu offset
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
Revert "powerpc: Replace __get_cpu_var uses"
percpu: Remove __this_cpu_ptr
clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
sparc: Replace __get_cpu_var uses
avr32: Replace __get_cpu_var with __this_cpu_write
blackfin: Replace __get_cpu_var uses
tile: Use this_cpu_ptr() for hardware counters
tile: Replace __get_cpu_var uses
powerpc: Replace __get_cpu_var uses
alpha: Replace __get_cpu_var
ia64: Replace __get_cpu_var uses
s390: cio driver &__get_cpu_var replacements
s390: Replace __get_cpu_var uses
mips: Replace __get_cpu_var uses
MIPS: Replace __get_cpu_var uses in FPU emulator.
arm: Replace __this_cpu_ptr with raw_cpu_ptr
...
This is illegal to use atomic_set(&page->_count, ...) even if we 'own'
the page. Other entities in the kernel need to use get_page_unless_zero()
to get a reference to the page before testing page properties, so we could
loose a refcount increment.
The only case it is valid is when page->_count is 0
Fixes: 540eb7bf0b ("net: Update alloc frag to reduce get/put page usage and recycle pages")
Signed-off-by: Eric Dumaze <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fix following warning.
Warning(.//net/core/skbuff.c:4142): No description found for parameter 'header_len'
Warning(.//net/core/skbuff.c:4142): No description found for parameter 'data_len'
Warning(.//net/core/skbuff.c:4142): No description found for parameter 'max_page_order'
Warning(.//net/core/skbuff.c:4142): No description found for parameter 'errcode'
Warning(.//net/core/skbuff.c:4142): No description found for parameter 'gfp_mask'
Acutually the descriptions exist, but missing "@" in front.
This problem start to happen when following commit was merged
into Linus's tree during 3.18-rc1 merge period.
commit 2e4e441071
net: add alloc_skb_with_frags() helper
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its unfortunate we have to walk again skb list to find the tail
after segmentation, even if data is probably hot in cpu caches.
skb_segment() can store the tail of the list into segs->prev,
and validate_xmit_skb_list() can immediately get the tail.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains another batch with Netfilter/IPVS updates
for net-next, they are:
1) Add abstracted ICMP codes to the nf_tables reject expression. We
introduce four reasons to reject using ICMP that overlap in IPv4
and IPv6 from the semantic point of view. This should simplify the
maintainance of dual stack rule-sets through the inet table.
2) Move nf_send_reset() functions from header files to per-family
nf_reject modules, suggested by Patrick McHardy.
3) We have to use IS_ENABLED(CONFIG_BRIDGE_NETFILTER) everywhere in the
code now that br_netfilter can be modularized. Convert remaining spots
in the network stack code.
4) Use rcu_barrier() in the nf_tables module removal path to ensure that
we don't leave object that are still pending to be released via
call_rcu (that may likely result in a crash).
5) Remove incomplete arch 32/64 compat from nft_compat. The original (bad)
idea was to probe the word size based on the xtables match/target info
size, but this assumption is wrong when you have to dump the information
back to userspace.
6) Allow to filter from prerouting and postrouting in the nf_tables bridge.
In order to emulate the ebtables NAT chains (which are actually simple
filter chains with no special semantics), we have support filtering from
this hooks too.
7) Add explicit module dependency between xt_physdev and br_netfilter.
This provides a way to detect if the user needs br_netfilter from
the configuration path. This should reduce the breakage of the
br_netfilter modularization.
8) Cleanup coding style in ip_vs.h, from Simon Horman.
9) Fix crash in the recently added nf_tables masq expression. We have
to register/unregister the notifiers to clean up the conntrack table
entries from the module init/exit path, not from the rule addition /
deletion path. From Arturo Borrero.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
SKB_FCLONE_UNAVAILABLE has overloaded meaning depending on type of skb.
1: If skb is allocated from head_cache, it indicates fclone is not available.
2: If skb is a companion fclone skb (allocated from fclone_cache), it indicates
it is available to be used.
To avoid confusion for case 2 above, this patch replaces
SKB_FCLONE_UNAVAILABLE with SKB_FCLONE_FREE where appropriate. For fclone
companion skbs, this indicates it is free for use.
SKB_FCLONE_UNAVAILABLE will now simply indicate skb is from head_cache and
cannot / will not have a companion fclone.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_gro_receive() is only called from tcp_gro_receive() which is
not in a module.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/usb/r8152.c
net/netfilter/nfnetlink.c
Both r8152 and nfnetlink conflicts were simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
In 34666d4 ("netfilter: bridge: move br_netfilter out of the core"),
the bridge netfilter code has been modularized.
Use IS_ENABLED instead of ifdef to cover the module case.
Fixes: 34666d4 ("netfilter: bridge: move br_netfilter out of the core")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fast clone cloning can actually avoid an atomic_inc(), if we
guarantee prior clone_ref value is 1.
This requires a change kfree_skbmem(), to perform the
atomic_dec_and_test() on clone_ref before setting fclone to
SKB_FCLONE_UNAVAILABLE.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Lets use a proper structure to clearly document and implement
skb fast clones.
Then, we might experiment more easily alternative layouts.
This patch adds a new skb_fclone_busy() helper, used by tcp and xfrm,
to stop leaking of implementation details.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 8a29111c7c ("net: gro: allow to build full sized skb")
I added a regression for linear skb that traditionally force GRO
to use the frag_list fallback.
Erez Shitrit found that at most two segments were aggregated and
the "if (skb_gro_len(p) != pinfo->gso_size)" test was failing.
This is because pinfo at this spot still points to the last skb in the
chain, instead of the first one, where we find the correct gso_size
information.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 8a29111c7c ("net: gro: allow to build full sized skb")
Reported-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With proliferation of bit fields in sk_buff, __copy_skb_header() became
quite expensive, showing as the most expensive function in a GSO
workload.
__copy_skb_header() performance is also critical for non GSO TCP
operations, as it is used from skb_clone()
This patch carefully moves all the fields that were not copied in a
separate zone : cloned, nohdr, fclone, peeked, head_frag, xmit_more
Then I moved all other fields and all other copied fields in a section
delimited by headers_start[0]/headers_end[0] section so that we
can use a single memcpy() call, inlined by compiler using long
word load/stores.
I also tried to make all copies in the natural orders of sk_buff,
to help hardware prefetching.
I made sure sk_buff size did not change.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cache skb_shinfo(skb) in a variable to avoid computing it multiple
times.
Reorganize the tests to remove one indentation level.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While profiling TCP stack, I noticed one useless atomic operation
in tcp_sendmsg(), caused by skb_header_release().
It turns out all current skb_header_release() users have a fresh skb,
that no other user can see, so we can avoid one atomic operation.
Introduce __skb_header_release() to clearly document this.
This gave me a 1.5 % improvement on TCP_RR workload.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Extract from sock_alloc_send_pskb() code building skb with frags,
so that we can reuse this in other contexts.
Intent is to use it from tcp_send_rcvq(), tcp_collapse(), ...
We also want to replace some skb_linearize() calls to a more reliable
strategy in pathological cases where we need to reduce number of frags.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can allow a segment with FIN to be aggregated,
if we take care to add tcp flags,
and if skb_try_coalesce() takes care of zero sized skbs.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a possible issue with the use, or lack thereof of sk_refcnt and
sk_wmem_alloc in the wifi ack status functionality.
Specifically if a socket were to request acknowledgements, and the socket
were to have sk_refcnt drop to 0 resulting in it waiting on sk_wmem_alloc
to reach 0 it would be possible to have sock_queue_err_skb orphan the last
buffer, resulting in __sk_free being called on the socket. After this the
buffer is enqueued on sk_error_queue, however the queue has already been
flushed resulting in at least a memory leak, if not a data corruption.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change adds some documentation to the call skb_clone_sk. This is
meant to help clarify the purpose of the function for other developers.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The phy timestamping takes a different path than the regular timestamping
does in that it will create a clone first so that the packets needing to be
timestamped can be placed in a queue, or the context block could be used.
In order to support these use cases I am pulling the core of the code out
so it can be used in other drivers beyond just phy devices.
In addition I have added a destructor named sock_efree which is meant to
provide a simple way for dropping the reference to skb exceptions that
aren't part of either the receive or send windows for the socket, and I
have removed some duplication in spots where this destructor could be used
in place of sock_edemux.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change merges the shared bits that exist between skb_tx_tstamp and
skb_complete_tx_timestamp. By doing this we can avoid the two diverging as
there were already changes pushed into skb_tx_tstamp that hadn't made it
into the other function.
In addition this resolves issues with the fact that
skb_complete_tx_timestamp was included in linux/skbuff.h even though it was
only compiled in if phy timestamping was enabled.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet