Introduce a simple helper function to replace a common pattern.
When accessing the GRO header, we fetch the pointer from frag0,
then test its validity and fetch it from the skb when necessary.
This leads to the pattern
skb_gro_header_fast -> skb_gro_header_hard -> skb_gro_header_slow
recurring many times throughout GRO code.
This patch replaces these patterns with a single inlined function
call, improving code readability.
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220823071034.GA56142@debian
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
While reading gro_normal_batch, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 323ebb61e3 ("net: use listified RX for handling GRO_NORMAL skbs")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following the cited commit, sparse started complaining about:
../include/net/gro.h:58:1: warning: directive in macro's argument list
../include/net/gro.h:59:1: warning: directive in macro's argument list
Fix that by moving the defines out of the struct_group() macro.
Fixes: de5a1f3ce4 ("net: gro: minor optimization for dev_gro_receive()")
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Acked-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While inspecting some perf report, I noticed that the compiler
emits suboptimal code for the napi CB initialization, fetching
and storing multiple times the memory for flags bitfield.
This is with gcc 10.3.1, but I observed the same with older compiler
versions.
We can help the compiler to do a nicer work clearing several
fields at once using an u32 alias. The generated code is quite
smaller, with the same number of conditional.
Before:
objdump -t net/core/gro.o | grep " F .text"
0000000000000bb0 l F .text 0000000000000357 dev_gro_receive
After:
0000000000000bb0 l F .text 000000000000033c dev_gro_receive
v1 -> v2:
- use struct_group (Alexander and Alex)
RFC -> v1:
- use __struct_group to delimit the zeroed area (Alexander)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vladimir reported csum issues after my recent change in skb_postpull_rcsum()
Issue here is the following:
initial skb->csum is the csum of
[part to be pulled][rest of packet]
Old code:
skb->csum = csum_sub(skb->csum, csum_partial(pull, pull_length, 0));
New code:
skb->csum = ~csum_partial(pull, pull_length, ~skb->csum);
This is broken if the csum of [pulled part]
happens to be equal to skb->csum, because end
result of skb->csum is 0 in new code, instead
of being 0xffffffff
David Laight suggested to use
skb->csum = -csum_partial(pull, pull_length, -skb->csum);
I based my patches on existing code present in include/net/seg6.h,
update_csum_diff4() and update_csum_diff16() which might need
a similar fix.
I guess that my tests, mostly pulling 40 bytes of IPv6 header
were not providing enough entropy to hit this bug.
v2: added wsum_negate() to make sparse happy.
Fixes: 29c3002644 ("net: optimize skb_postpull_rcsum()")
Fixes: 0bd28476f6 ("gro: optimize skb_gro_postpull_rcsum()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Cc: David Lebrun <dlebrun@google.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20211204045356.3659278-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We can leverage third argument to csum_partial():
X = csum_sub(X, csum_partial(start, len, 0));
-->
X = csum_add(X, ~csum_partial(start, len, 0));
-->
X = ~csum_partial(start, len, ~X);
This removes one add/adc pair and its dependency against the carry flag.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is needed for some arches, as reported by Geert Uytterhoeven,
Randy Dunlap and Stephen Rothwell
Fixes: 4721031c35 ("net: move gro definitions to include/net/gro.h")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20211117100130.2368319-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move gro code and data from net/core/dev.c to net/core/gro.c
to ease maintenance.
gro_normal_list() and gro_normal_one() are inlined
because they are called from both files.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/gro.c will contain all core gro functions,
to shrink net/core/skbuff.c and net/core/dev.c
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/netdevice.h became too big, move gro stuff
into include/net/gro.h
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
call_gro_receive() is used to limit GRO recursion, but it works only
with callback pointers.
There's a combined version of call_gro_receive() + INDIRECT_CALL_2()
in <net/inet_common.h>, but it doesn't check for IPv6 modularity.
Add a similar new helper to cover both of these. It can and will be
used to avoid retpoline overhead when IP header lies behind another
offloaded proto.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
If some source file includes <net/gro.h>, but doesn't include
<linux/indirect_call_wrapper.h>:
In file included from net/8021q/vlan_core.c:7:
./include/net/gro.h:6:1: warning: data definition has no type or storage class
6 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
| ^~~~~~~~~~~~~~~~~~~~~~~~~
./include/net/gro.h:6:1: error: type defaults to ‘int’ in declaration of ‘INDIRECT_CALLABLE_DECLARE’ [-Werror=implicit-int]
[...]
Include <linux/indirect_call_wrapper.h> directly. It's small and
won't pull lots of dependencies.
Also add some incomplete struct declarations to be fully stacked.
Fixes: 04f00ab227 ("net/core: move gro function declarations to separate header ")
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
