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authorLiping Zhang <zlpnobody@gmail.com>2017-01-07 21:33:55 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2017-01-18 20:32:43 +0100
commitf169fd695b192dd7b23aff8e69d25a1bc881bbfa (patch)
tree2fb01bb5f8a59e9c45949a84ca79af221614a49e /net/tipc/sysctl.c
parent9a6d87626252496311cd122aaa9fbf21ae19e449 (diff)
netfilter: nft_meta: deal with PACKET_LOOPBACK in netdev family
After adding the following nft rule, then ping 224.0.0.1: # nft add rule netdev t c pkttype host counter The warning complain message will be printed out again and again: WARNING: CPU: 0 PID: 10182 at net/netfilter/nft_meta.c:163 \ nft_meta_get_eval+0x3fe/0x460 [nft_meta] [...] Call Trace: <IRQ> dump_stack+0x85/0xc2 __warn+0xcb/0xf0 warn_slowpath_null+0x1d/0x20 nft_meta_get_eval+0x3fe/0x460 [nft_meta] nft_do_chain+0xff/0x5e0 [nf_tables] So we should deal with PACKET_LOOPBACK in netdev family too. For ipv4, convert it to PACKET_BROADCAST/MULTICAST according to the destination address's type; For ipv6, convert it to PACKET_MULTICAST directly. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/tipc/sysctl.c')
0 files changed, 0 insertions, 0 deletions
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2025-01-09 03:06:00 +0000
the result. However, an even simpler model is to just use a regular atomic "and" to clear the lock bit, and then the sign bit in eflags will indicate the resulting state of the unrelated bit #7. So by moving the PageWaiters bit up to bit #7, we can atomically clear the lock bit and test the waiters bit on x86 too. And architectures with LL/SC (which is all the usual RISC suspects), the particular bit doesn't matter, so they are fine with this approach too. This avoids the extra access to the same atomic word, and thus avoids the costly stall at page unlock time. The only downside is that the interface ends up being a bit odd and specialized: clear a bit in a byte, and test the sign bit. Nick doesn't love the resulting name of the new primitive, but I'd rather make the name be descriptive and very clear about the limitation imposed by trying to work across all relevant architectures than make it be some generic thing that doesn't make the odd semantics explicit. So this introduces the new architecture primitive clear_bit_unlock_is_negative_byte(); and adds the trivial implementation for x86. We have a generic non-optimized fallback (that just does a "clear_bit()"+"test_bit(7)" combination) which can be overridden by any architecture that can do better. According to Nick, Power has the same hickup x86 has, for example, but some other architectures may not even care. All these optimizations mean that my page locking stress-test (which is just executing a lot of small short-lived shell scripts: "make test" in the git source tree) no longer makes our page locking look horribly bad. Before all these optimizations, just the unlock_page() costs were just over 3% of all CPU overhead on "make test". After this, it's down to 0.66%, so just a quarter of the cost it used to be. (The difference on NUMA is bigger, but there this micro-optimization is likely less noticeable, since the big issue on NUMA was not the accesses to 'struct page', but the waitqueue accesses that were already removed by Nick's earlier commit). Acked-by: Nick Piggin <npiggin@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Andrew Lutomirski <luto@kernel.org> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/acpi/platform/acenv.h')