Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756005AbbHDJHa (ORCPT ); Tue, 4 Aug 2015 05:07:30 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:7593 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932557AbbHDI6u (ORCPT ); Tue, 4 Aug 2015 04:58:50 -0400 From: Kaixu Xia To: , , , , , , , CC: , , , , , Subject: [PATCH v6 0/4] bpf: Introduce the new ability of eBPF programs to access hardware PMU counter Date: Tue, 4 Aug 2015 08:58:12 +0000 Message-ID: <1438678696-88289-1-git-send-email-xiakaixu@huawei.com> X-Mailer: git-send-email 1.8.3.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.250] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.55C07EC6.0017,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: b0d11ebb1b1c0473ddf662e54a687efc Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5107 Lines: 124 Previous patch v5 url: https://lkml.org/lkml/2015/7/31/299 changes in V6: - make the Patch 1/4 commit message more meaning and readable; - remove the unnecessary comment in Patch 2/4 and make it clean; - declare the function perf_event_release_kernel() in include/ linux/perf_event.h to fix the build error when CONFIG_PERF_EVENTS isn't configured in Patch 2/4; - add function perf_event_attrs() to get the struct perf_event_attr in Patch 2/4. - move the related code from kernel/trace/bpf_trace.c to kernel/ events/core.c and add function perf_event_read_internal() to avoid poking inside of the event outside of perf code in Patch 3/4; - generial the func & map match-pair with an array in Patch 3/4; changes in V5: - move struct fd_array_map_ops* fd_ops to bpf_map; - move array perf event decrement refcnt function to map_free; - fix the NULL ptr of perf_event_get(); - move bpf_perf_event_read() to kernel/bpf/bpf_trace.c; - get rid of the remaining struct bpf_prog; - move the unnecessay cast on void *; changes in V4: - make the bpf_prog_array_map more generic; - fix the bug of event refcnt leak; - use more useful errno in bpf_perf_event_read(); changes in V3: - collapse V2 patches 1-3 into one; - drop the function map->ops->map_traverse_elem() and release the struct perf_event in map_free; - only allow to access bpf_perf_event_read() from programs; - update the perf_event_array_map elem via xchg(); - pass index directly to bpf_perf_event_read() instead of MAP_KEY; changes in V2: - put atomic_long_inc_not_zero() between fdget() and fdput(); - limit the event type to PERF_TYPE_RAW and PERF_TYPE_HARDWARE; - Only read the event counter on current CPU or on current process; - add new map type BPF_MAP_TYPE_PERF_EVENT_ARRAY to store the pointer to the struct perf_event; - according to the perf_event_map_fd and key, the function bpf_perf_event_read() can get the Hardware PMU counter value; Patch 4/4 is a simple example and shows how to use this new eBPF programs ability. The PMU counter data can be found in /sys/kernel/debug/tracing/trace(trace_pipe).(the cycles PMU value when 'kprobe/sys_write' sampling) $ cat /sys/kernel/debug/tracing/trace_pipe $ ./tracex6 ... syslog-ng-548 [000] d..1 76.905673: : CPU-0 681765271 syslog-ng-548 [000] d..1 76.905690: : CPU-0 681787855 syslog-ng-548 [000] d..1 76.905707: : CPU-0 681810504 syslog-ng-548 [000] d..1 76.905725: : CPU-0 681834771 syslog-ng-548 [000] d..1 76.905745: : CPU-0 681859519 syslog-ng-548 [000] d..1 76.905766: : CPU-0 681890419 syslog-ng-548 [000] d..1 76.905783: : CPU-0 681914045 syslog-ng-548 [000] d..1 76.905800: : CPU-0 681935950 syslog-ng-548 [000] d..1 76.905816: : CPU-0 681958299 ls-690 [005] d..1 82.241308: : CPU-5 3138451 sh-691 [004] d..1 82.244570: : CPU-4 7324988 <...>-699 [007] d..1 99.961387: : CPU-7 3194027 <...>-695 [003] d..1 99.961474: : CPU-3 288901 <...>-695 [003] d..1 99.961541: : CPU-3 383145 <...>-695 [003] d..1 99.961591: : CPU-3 450365 <...>-695 [003] d..1 99.961639: : CPU-3 515751 <...>-695 [003] d..1 99.961686: : CPU-3 579047 ... The detail of patches is as follow: Patch 1/4 rewrites part of the bpf_prog_array map code and make it more generic; Patch 2/4 introduces a new bpf map type. This map only stores the pointer to struct perf_event; Patch 3/4 implements function bpf_perf_event_read() that get the selected hardware PMU conuter; Patch 4/4 gives a simple example. Kaixu Xia (3): bpf: Add new bpf map type to store the pointer to struct perf_event bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter samples/bpf: example of get selected PMU counter value Wang Nan (1): bpf: Make the bpf_prog_array_map more generic arch/x86/net/bpf_jit_comp.c | 6 +- include/linux/bpf.h | 10 +++- include/linux/perf_event.h | 10 ++++ include/uapi/linux/bpf.h | 2 + kernel/bpf/arraymap.c | 137 ++++++++++++++++++++++++++++++++++---------- kernel/bpf/core.c | 2 +- kernel/bpf/syscall.c | 2 +- kernel/bpf/verifier.c | 49 +++++++++++----- kernel/events/core.c | 44 ++++++++++++++ kernel/trace/bpf_trace.c | 31 ++++++++++ samples/bpf/Makefile | 4 ++ samples/bpf/bpf_helpers.h | 2 + samples/bpf/tracex6_kern.c | 26 +++++++++ samples/bpf/tracex6_user.c | 68 ++++++++++++++++++++++ 14 files changed, 340 insertions(+), 53 deletions(-) create mode 100644 samples/bpf/tracex6_kern.c create mode 100644 samples/bpf/tracex6_user.c -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/