From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei Subject: [PATCH v2 0/3] bpf: hash: use per-bucket spinlock Date: Tue, 29 Dec 2015 22:40:24 +0800 Message-ID: <1451400027-28892-1-git-send-email-tom.leiming@gmail.com> Cc: "David S. Miller" , netdev@vger.kernel.org, Daniel Borkmann To: linux-kernel@vger.kernel.org, Alexei Starovoitov Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi, This patchset tries to optimize ebpf hash map, and follows the idea: Both htab_map_update_elem() and htab_map_delete_elem() can be called from eBPF program, and they may be in kernel hot path, it isn't efficient to use a per-hashtable lock in this two helpers, so this patch converts the lock into per-bucket spinlock. With this patchset, looks the performance penalty from eBPF decreased a lot, see the following test: 1) run 'tools/biolatency' of bcc before running block test; 2) run fio to test block throught over /dev/nullb0, (randread, 16jobs, libaio, 4k bs) and the test box is one 24cores(dual sockets) VM server: - without patchset: 607K IOPS - with this patchset: 1184K IOPS - without running eBPF prog: 1492K IOPS TODO: - remove the per-hashtable atomic counter V2: - fix checking on buckets size V1: - fix the wrong 3/3 patch kernel/bpf/hashtab.c | 64 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 38 insertions(+), 26 deletions(-) Thanks, Ming Lei