Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Modify trace function from generic_file_read_iter() to ext4_file_read_iter() #1818

Merged
merged 3 commits into from
Jun 14, 2018
Merged

Modify trace function from generic_file_read_iter() to ext4_file_read_iter() #1818

Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
a607b42
modify ext4slower.py for 4.10+ version
kernel-z Jun 13, 2018
d2b05f9
modify ext4slower.py for 4.10+ version
kernel-z Jun 13, 2018
1b96470
#1818
kernel-z Jun 14, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
modify ext4slower.py for 4.10+ version
  • Loading branch information
@kernel-z
kernel-z committed Jun 13, 2018
commit a607b421447823aae8fe3cd28a61add1e850c52d
20 changes: 17 additions & 3 deletions tools/ext4slower.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
#
# 11-Feb-2016 Brendan Gregg Created this.
# 15-Oct-2016 Dina Goldshtein -p to filter by process ID.
# 13-Jun-2018 Joe Yin modify generic_file_read_iter to ext4_file_read_iter.

from __future__ import print_function
from bcc import BPF
Expand All @@ -40,6 +41,7 @@
./ext4slower -j 1 # ... 1 ms, parsable output (csv)
./ext4slower 0 # trace all operations (warning: verbose)
./ext4slower -p 185 # trace PID 185 only
./ext4slower -n # trace Linux 4.10+
"""
parser = argparse.ArgumentParser(
description="Trace common ext4 file operations slower than a threshold",
Expand All @@ -49,6 +51,8 @@
help="just print fields: comma-separated values")
parser.add_argument("-p", "--pid",
help="trace this PID only")
parser.add_argument("-n", "--newver", action="store_true",
help="trace Linux 4.10+")
parser.add_argument("min_ms", nargs="?", default='10',
help="minimum I/O duration to trace, in ms (default 10)")
parser.add_argument("--ebpf", action="store_true",
Expand All @@ -57,6 +61,7 @@
min_ms = int(args.min_ms)
pid = args.pid
csv = args.csv
newver = args.newver
debug = 0

# define BPF program
Expand Down Expand Up @@ -100,6 +105,9 @@
// The current ext4 (Linux 4.5) uses generic_file_read_iter(), instead of it's
// own function, for reads. So we need to trace that and then filter on ext4,
// which I do by checking file->f_op.
// The new Linux version (since form 4.10) uses ext4_file_read_iter(), And if the 'CONFIG_FS_DAX'
// is not set ,it will call generic_file_read_iter(), else it will call ext4_dax_read_iter(), and
// trace generic_file_read_iter() will fail.
int trace_read_entry(struct pt_regs *ctx, struct kiocb *iocb)
{
u64 id = bpf_get_current_pid_tgid();
Expand All @@ -111,7 +119,7 @@
// ext4 filter on file->f_op == ext4_file_operations
struct file *fp = iocb->ki_filp;
if ((u64)fp->f_op != EXT4_FILE_OPERATIONS)
return 0;
return 0;

// store filep and timestamp by id
struct val_t val = {};
Expand Down Expand Up @@ -321,11 +329,17 @@ def print_event(cpu, data, size):
b = BPF(text=bpf_text)

# Common file functions. See earlier comment about generic_file_read_iter().
b.attach_kprobe(event="generic_file_read_iter", fn_name="trace_read_entry")
if (newver):
b.attach_kprobe(event="ext4_file_read_iter", fn_name="trace_read_entry")
else:
b.attach_kprobe(event="generic_file_read_iter", fn_name="trace_read_entry")
b.attach_kprobe(event="ext4_file_write_iter", fn_name="trace_write_entry")
b.attach_kprobe(event="ext4_file_open", fn_name="trace_open_entry")
b.attach_kprobe(event="ext4_sync_file", fn_name="trace_fsync_entry")
b.attach_kretprobe(event="generic_file_read_iter", fn_name="trace_read_return")
if (newver):
b.attach_kretprobe(event="ext4_file_read_iter", fn_name="trace_read_return")
else:
b.attach_kretprobe(event="generic_file_read_iter", fn_name="trace_read_return")
b.attach_kretprobe(event="ext4_file_write_iter", fn_name="trace_write_return")
b.attach_kretprobe(event="ext4_file_open", fn_name="trace_open_return")
b.attach_kretprobe(event="ext4_sync_file", fn_name="trace_fsync_return")
Expand Down