Re: [PATCH v4 00/10] tracing: introducing eventfs

Ajay Kaher
2023-07-16T17:32:45Z

> On 15-Jul-2023, at 4:28 AM, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> !! External Email
>
> On Thu, 13 Jul 2023 17:03:14 +0530
> Ajay Kaher <akaher@vmware.com> wrote:
>
>> Events Tracing infrastructure contains lot of files, directories
>> (internally in terms of inodes, dentries). And ends up by consuming
>> memory in MBs. We can have multiple events of Events Tracing, which
>> further requires more memory.
>>
>> Instead of creating inodes/dentries, eventfs could keep meta-data and
>> skip the creation of inodes/dentries. As and when require, eventfs will
>> create the inodes/dentries only for required files/directories.
>> Also eventfs would delete the inodes/dentries once no more requires
>> but preserve the meta data.
>>
>> Tracing events took ~9MB, with this approach it took ~4.5MB
>> for ~10K files/dir.
>
> I think we are very close to getting this in for the next merge window. I
> ran several tests and so far it's holding up!
>
> I made a bunch of nits for this series, but nothing major. Mostly fixing up
> change logs and comments, as well as some naming conventions and
> reorganizing the series a little bit.
>
> Anyway, I'm hoping that v5 will be ready to go into linux-next.
>
> Thanks a lot Ajay for working on this!

Thanks Steve, hopefully I will fix all the pending nits in v5.
Here is the checkpatch.pl report:

./scripts/checkpatch.pl v4/*
--------------------------
v4/0000-cover-letter.patch
--------------------------
total: 0 errors, 0 warnings, 0 lines checked

v4/0000-cover-letter.patch has no obvious style problems and is ready for submission.
------------------------------------------------------------------
v4/0001-tracing-Require-all-trace-events-to-have-a-TRACE_SYS.patch
------------------------------------------------------------------
total: 0 errors, 0 warnings, 22 lines checked

v4/0001-tracing-Require-all-trace-events-to-have-a-TRACE_SYS.patch has no obvious style problems and is ready for submission.
--------------------------------------------------
v4/0002-tracefs-Rename-some-tracefs-function.patch
--------------------------------------------------
total: 0 errors, 0 warnings, 71 lines checked

v4/0002-tracefs-Rename-some-tracefs-function.patch has no obvious style problems and is ready for submission.
--------------------------------------------------------------
v4/0003-eventfs-Implement-eventfs-dir-creation-functions.patch
--------------------------------------------------------------
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#52:
new file mode 100644

WARNING: Symbolic permissions 'S_IRWXU | S_IRUGO | S_IXUGO' are not preferred. Consider using octal permissions '0755'.
#194: FILE: fs/tracefs/event_inode.c:138:
+ inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;

WARNING: Symbolic permissions 'S_IRWXU | S_IRUGO | S_IXUGO' are not preferred. Consider using octal permissions '0755'.
#229: FILE: fs/tracefs/event_inode.c:173:
+ S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,

WARNING: Symbolic permissions 'S_IRWXU | S_IRUGO | S_IXUGO' are not preferred. Consider using octal permissions '0755'.
#261: FILE: fs/tracefs/event_inode.c:205:
+ S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,

total: 0 errors, 4 warnings, 297 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.

v4/0003-eventfs-Implement-eventfs-dir-creation-functions.patch has style problems, please review.
----------------------------------------------------------
v4/0004-eventfs-Implement-eventfs-file-add-functions.patch
----------------------------------------------------------
total: 0 errors, 0 warnings, 101 lines checked

v4/0004-eventfs-Implement-eventfs-file-add-functions.patch has no obvious style problems and is ready for submission.
------------------------------------------------------------------
v4/0005-eventfs-Implement-eventfs-file-directory-remove-func.patch
------------------------------------------------------------------
total: 0 errors, 0 warnings, 129 lines checked

v4/0005-eventfs-Implement-eventfs-file-directory-remove-func.patch has no obvious style problems and is ready for submission.
------------------------------------------------------------------
v4/0006-eventfs-Implement-functions-to-create-eventfs-files-.patch
------------------------------------------------------------------
total: 0 errors, 0 warnings, 182 lines checked

v4/0006-eventfs-Implement-functions-to-create-eventfs-files-.patch has no obvious style problems and is ready for submission.
------------------------------------------------------------------
v4/0007-eventfs-Implement-eventfs-lookup-read-open-functions.patch
------------------------------------------------------------------
total: 0 errors, 0 warnings, 224 lines checked

v4/0007-eventfs-Implement-eventfs-lookup-read-open-functions.patch has no obvious style problems and is ready for submission.
---------------------------------------------------
v4/0008-eventfs-Implement-tracefs_inode_cache.patch
---------------------------------------------------
total: 0 errors, 0 warnings, 68 lines checked

v4/0008-eventfs-Implement-tracefs_inode_cache.patch has no obvious style problems and is ready for submission.
----------------------------------------------------
v4/0009-eventfs-Move-tracing-events-to-eventfs.patch
----------------------------------------------------
total: 0 errors, 0 warnings, 241 lines checked

v4/0009-eventfs-Move-tracing-events-to-eventfs.patch has no obvious style problems and is ready for submission.
-----------------------------------------------------
v4/0010-test-ftrace-Fix-kprobe-test-for-eventfs.patch
-----------------------------------------------------
total: 0 errors, 0 warnings, 32 lines checked

v4/0010-test-ftrace-Fix-kprobe-test-for-eventfs.patch has no obvious style problems and is ready for submission.

-Ajay