Bug 2219193

Summary: bpf-readahead fails to run
Product: Red Hat Enterprise Linux 9 Reporter: Carlos Rodriguez-Fernandez <carlosrodrifernandez>
Component: bccAssignee: Jerome Marchand <jmarchan>
Status: ASSIGNED --- QA Contact:
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Priority: unspecified    
Version: CentOS StreamCC: bfubel, bstinson, ctrautma, jmarchan, jwboyer, ldoskova, rdossant
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Description Carlos Rodriguez-Fernandez 2023-07-02 22:42:30 UTC 
Description of problem:

bpf-readahead fails to run.

```
bpf-readahead -d 1
failed to set attach target for do_page_cache_ra: No such process
```

Version-Release number of selected component (if applicable):
Name         : libbpf-tools
Version      : 0.26.0
Release      : 3.el9

How reproducible:

Steps to Reproduce:
1. Download Centos Stream 9 QCOW2 and run it
2. run dnf install libbpf-tools
3. run bpf-readahead -d 1

Actual results:

```
failed to set attach target for do_page_cache_ra: No such process
```

Expected results:
It doesn't error but works as intended

Additional info:
Comment 1 Jerome Marchand 2023-08-09 10:11:01 UTC 
(In reply to Carlos Rodriguez-Fernandez from comment #0)
> Description of problem:
> 
> bpf-readahead fails to run.
> 
> ```
> bpf-readahead -d 1
> failed to set attach target for do_page_cache_ra: No such process
> ```
> 
> Version-Release number of selected component (if applicable):
> Name         : libbpf-tools
> Version      : 0.26.0
> Release      : 3.el9
> 
> How reproducible:
> 
> Steps to Reproduce:
> 1. Download Centos Stream 9 QCOW2 and run it
> 2. run dnf install libbpf-tools
> 3. run bpf-readahead -d 1
> 
> Actual results:
> 
> ```
> failed to set attach target for do_page_cache_ra: No such process
> ```

do_page_cache_ra() is a fairly small static function. Looks like it got inlined. It doesn't look it's going to be easy to fix.

> 
> Expected results:
> It doesn't error but works as intended
> 
> Additional info:
Comment 2 Jerome Marchand 2023-08-09 10:24:05 UTC 
Upstream issue:
https://github.com/iovisor/bcc/issues/4700