linux/net/openvswitch/flow_table.c, branch v3.19

net: replace remaining users of arch_fast_hash with jhash

2014-12-10T20:17:45Z

This patch effectively reverts commit 500f80872645 ("net: ovs: use CRC32 accelerated flow hash if available"), and other remaining arch_fast_hash() users such as from nfsd via commit 6282cd565553 ("NFSD: Don't hand out delegations for 30 seconds after recalling them.") where it has been used as a hash function for bloom filtering. While we think that these users are actually not much of concern, it has been requested to remove the arch_fast_hash() library bits that arose from [1] entirely as per recent discussion [2]. The main argument is that using it as a hash may introduce bias due to its linearity (see avalanche criterion) and thus makes it less clear (though we tried to document that) when this security/performance trade-off is actually acceptable for a general purpose library function. Lets therefore avoid any further confusion on this matter and remove it to prevent any future accidental misuse of it. For the time being, this is going to make hashing of flow keys a bit more expensive in the ovs case, but future work could reevaluate a different hashing discipline. [1] https://patchwork.ozlabs.org/patch/299369/ [2] https://patchwork.ozlabs.org/patch/418756/ Cc: Neil Brown Cc: Francesco Fusco Cc: Jesse Gross Cc: Thomas Graf Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

openvswitch: Constify various function arguments

2014-11-10T02:58:44Z

Help produce better optimized code. Signed-off-by: Thomas Graf Signed-off-by: Pravin B Shelar

openvswitch: Move table destroy to dp-rcu callback.

2014-11-06T07:52:34Z

Ths simplifies flow-table-destroy API. No need to pass explicit parameter about context. Signed-off-by: Pravin B Shelar Acked-by: Thomas Graf

openvswitch: Use exact lookup for flow_get and flow_del.

2014-07-01T03:47:15Z

Due to the race condition in userspace, there is chance that two overlapping megaflows could be installed in datapath. And this causes userspace unable to delete the less inclusive megaflow flow even after it timeout, since the flow_del logic will stop at the first match of masked flow. This commit fixes the bug by making the kernel flow_del and flow_get logic check all masks in that case. Introduced by 03f0d916a (openvswitch: Mega flow implementation). Signed-off-by: Alex Wang Acked-by: Andy Zhou Signed-off-by: Pravin B Shelar

openvswitch: Fix typo.

2014-05-22T23:27:35Z

Incorrect struct name was confusing, even though otherwise inconsequental. Signed-off-by: Jarno Rajahalme Signed-off-by: Pravin B Shelar

openvswitch: Make flow mask removal symmetric.

2014-05-22T23:27:35Z

Masks are inserted when flows are inserted to the table, so it is logical to correspondingly remove masks when flows are removed from the table, in ovs_flow_table_remove(). This allows ovs_flow_free() to be called without locking, which will be used by later patches. Signed-off-by: Jarno Rajahalme Signed-off-by: Pravin B Shelar

openvswitch: Per NUMA node flow stats.

2014-05-16T20:40:29Z

Keep kernel flow stats for each NUMA node rather than each (logical) CPU. This avoids using the per-CPU allocator and removes most of the kernel-side OVS locking overhead otherwise on the top of perf reports and allows OVS to scale better with higher number of threads. With 9 handlers and 4 revalidators netperf TCP_CRR test flow setup rate doubles on a server with two hyper-threaded physical CPUs (16 logical cores each) compared to the current OVS master. Tested with non-trivial flow table with a TCP port match rule forcing all new connections with unique port numbers to OVS userspace. The IP addresses are still wildcarded, so the kernel flows are not considered as exact match 5-tuple flows. This type of flows can be expected to appear in large numbers as the result of more effective wildcarding made possible by improvements in OVS userspace flow classifier. Perf results for this test (master): Events: 305K cycles + 8.43% ovs-vswitchd [kernel.kallsyms] [k] mutex_spin_on_owner + 5.64% ovs-vswitchd [kernel.kallsyms] [k] __ticket_spin_lock + 4.75% ovs-vswitchd ovs-vswitchd [.] find_match_wc + 3.32% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_lock + 2.61% ovs-vswitchd [kernel.kallsyms] [k] pcpu_alloc_area + 2.19% ovs-vswitchd ovs-vswitchd [.] flow_hash_in_minimask_range + 2.03% swapper [kernel.kallsyms] [k] intel_idle + 1.84% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_unlock + 1.64% ovs-vswitchd ovs-vswitchd [.] classifier_lookup + 1.58% ovs-vswitchd libc-2.15.so [.] 0x7f4e6 + 1.07% ovs-vswitchd [kernel.kallsyms] [k] memset + 1.03% netperf [kernel.kallsyms] [k] __ticket_spin_lock + 0.92% swapper [kernel.kallsyms] [k] __ticket_spin_lock ... And after this patch: Events: 356K cycles + 6.85% ovs-vswitchd ovs-vswitchd [.] find_match_wc + 4.63% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_lock + 3.06% ovs-vswitchd [kernel.kallsyms] [k] __ticket_spin_lock + 2.81% ovs-vswitchd ovs-vswitchd [.] flow_hash_in_minimask_range + 2.51% ovs-vswitchd libpthread-2.15.so [.] pthread_mutex_unlock + 2.27% ovs-vswitchd ovs-vswitchd [.] classifier_lookup + 1.84% ovs-vswitchd libc-2.15.so [.] 0x15d30f + 1.74% ovs-vswitchd [kernel.kallsyms] [k] mutex_spin_on_owner + 1.47% swapper [kernel.kallsyms] [k] intel_idle + 1.34% ovs-vswitchd ovs-vswitchd [.] flow_hash_in_minimask + 1.33% ovs-vswitchd ovs-vswitchd [.] rule_actions_unref + 1.16% ovs-vswitchd ovs-vswitchd [.] hindex_node_with_hash + 1.16% ovs-vswitchd ovs-vswitchd [.] do_xlate_actions + 1.09% ovs-vswitchd ovs-vswitchd [.] ofproto_rule_ref + 1.01% netperf [kernel.kallsyms] [k] __ticket_spin_lock ... There is a small increase in kernel spinlock overhead due to the same spinlock being shared between multiple cores of the same physical CPU, but that is barely visible in the netperf TCP_CRR test performance (maybe ~1% performance drop, hard to tell exactly due to variance in the test results), when testing for kernel module throughput (with no userspace activity, handful of kernel flows). On flow setup, a single stats instance is allocated (for the NUMA node 0). As CPUs from multiple NUMA nodes start updating stats, new NUMA-node specific stats instances are allocated. This allocation on the packet processing code path is made to never block or look for emergency memory pools, minimizing the allocation latency. If the allocation fails, the existing preallocated stats instance is used. Also, if only CPUs from one NUMA-node are updating the preallocated stats instance, no additional stats instances are allocated. This eliminates the need to pre-allocate stats instances that will not be used, also relieving the stats reader from the burden of reading stats that are never used. Signed-off-by: Jarno Rajahalme Acked-by: Pravin B Shelar Signed-off-by: Jesse Gross

openvswitch: Remove 5-tuple optimization.

2014-05-16T20:40:29Z

The 5-tuple optimization becomes unnecessary with a later per-NUMA node stats patch. Remove it first to make the changes easier to grasp. Signed-off-by: Jarno Rajahalme Signed-off-by: Jesse Gross

openvswitch: use const in some local vars and casts

2014-05-16T20:40:28Z

In few functions, const formal parameters are assigned or cast to non-const. These changes suppress warnings if compiled with -Wcast-qual. Signed-off-by: Daniele Di Proietto Signed-off-by: Jesse Gross

openvswitch: Fix ovs_flow_free() ovs-lock assert.

2014-02-05T06:21:45Z

ovs_flow_free() is not called under ovs-lock during packet execute path (ovs_packet_cmd_execute()). Since packet execute does not touch flow->mask, there is no need to take that lock either. So move assert in case where flow->mask is checked. Found by code inspection. Signed-off-by: Pravin B Shelar Signed-off-by: Jesse Gross