aboutsummaryrefslogtreecommitdiff
path: root/Documentation/virt/kvm
diff options
context:
space:
mode:
authorJakub Kicinski2022-08-24 19:30:19 -0700
committerJakub Kicinski2022-08-24 19:30:19 -0700
commitc21e1bf4d8104fb77bbd99f3d1276c0d7c9b28d9 (patch)
tree73ff51aa3bc284c611e346b14f4ebe8b90f251b8 /Documentation/virt/kvm
parent0bf73255d3a3cf3b0416e95f2c9f7c53095c2e1a (diff)
parent1be9ac87a75a4fc0e2cc254e412d2d67a58a7191 (diff)
Merge branch 'add-a-second-bind-table-hashed-by-port-and-address'
Joanne Koong says: ==================== Add a second bind table hashed by port and address Currently, there is one bind hashtable (bhash) that hashes by port only. This patchset adds a second bind table (bhash2) that hashes by port and address. The motivation for adding bhash2 is to expedite bind requests in situations where the port has many sockets in its bhash table entry (eg a large number of sockets bound to different addresses on the same port), which makes checking bind conflicts costly especially given that we acquire the table entry spinlock while doing so, which can cause softirq cpu lockups and can prevent new tcp connections. We ran into this problem at Meta where the traffic team binds a large number of IPs to port 443 and the bind() call took a significant amount of time which led to cpu softirq lockups, which caused packet drops and other failures on the machine. When experimentally testing this on a local server for ~24k sockets bound to the port, the results seen were: ipv4: before - 0.002317 seconds with bhash2 - 0.000020 seconds ipv6: before - 0.002431 seconds with bhash2 - 0.000021 seconds The additions to the initial bhash2 submission [0] are: * Updating bhash2 in the cases where a socket's rcv saddr changes after it has * been bound * Adding locks for bhash2 hashbuckets [0] https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/ v3: https://lore.kernel.org/netdev/20220722195406.1304948-2-joannelkoong@gmail.com/ v2: https://lore.kernel.org/netdev/20220712235310.1935121-1-joannelkoong@gmail.com/ v1: https://lore.kernel.org/netdev/20220623234242.2083895-2-joannelkoong@gmail.com/ ==================== Link: https://lore.kernel.org/r/20220822181023.3979645-1-joannelkoong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation/virt/kvm')
0 files changed, 0 insertions, 0 deletions