From 2ada4cee035c4d07391faa870a5df1874d657b65 Mon Sep 17 00:00:00 2001

From: Tejun Heo <tj@kernel.org>

Date: Thu, 27 Jan 2022 06:25:31 -1000

Subject: [PATCH 2/3] biolatpcts: Build fixes on recent kernels

* `struct request` definition recently moved from blkdev.h to blk-mq.h

  breaking both tools/biolatpcts and examples/tracing/biolatpcts. Fix them

  by also including blk-mq.h.

* blk_account_io_done() got split into two parts - inline condition checks

  and the actual accounting with the latter now done in

  __blk_account_io_done(). The kprobe attachment needs to be conditionalized

  to work across the change. tools/biolatpcts was already updated but

  examples/tracing/biolatpcts wasn't. Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>

---

 examples/tracing/biolatpcts.py | 6 +++++-

 tools/biolatpcts.py            | 1 +

 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/examples/tracing/biolatpcts.py b/examples/tracing/biolatpcts.py

index c9bb834e..68a59516 100755

--- a/examples/tracing/biolatpcts.py

+++ b/examples/tracing/biolatpcts.py

@@ -11,6 +11,7 @@ from time import sleep

 bpf_source = """

 #include <linux/blk_types.h>

+#include <linux/blk-mq.h>

 #include <linux/blkdev.h>

 #include <linux/time64.h>

@@ -45,7 +46,10 @@ void kprobe_blk_account_io_done(struct pt_regs *ctx, struct request *rq, u64 now

 """

 bpf = BPF(text=bpf_source)

-bpf.attach_kprobe(event='blk_account_io_done', fn_name='kprobe_blk_account_io_done')

+if BPF.get_kprobe_functions(b'__blk_account_io_done'):

+    bpf.attach_kprobe(event="__blk_account_io_done", fn_name="kprobe_blk_account_io_done")

+else:

+    bpf.attach_kprobe(event="blk_account_io_done", fn_name="kprobe_blk_account_io_done")

 cur_lat_100ms = bpf['lat_100ms']

 cur_lat_1ms = bpf['lat_1ms']

diff --git a/tools/biolatpcts.py b/tools/biolatpcts.py

index a2f59592..0f334419 100755

--- a/tools/biolatpcts.py

+++ b/tools/biolatpcts.py

@@ -56,6 +56,7 @@ parser.add_argument('--verbose', '-v', action='count', default = 0)

 bpf_source = """

 #include <linux/blk_types.h>

 #include <linux/blkdev.h>

+#include <linux/blk-mq.h>

 #include <linux/time64.h>

 BPF_PERCPU_ARRAY(rwdf_100ms, u64, 400);

-- 

2.35.1