Bug 604887 - sysfs_poll() does not treat /sys as regular files
Summary: sysfs_poll() does not treat /sys as regular files
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.5
Hardware: All
OS: Linux
low
medium
Target Milestone: rc
: ---
Assignee: Red Hat Kernel Manager
QA Contact: Red Hat Kernel QE team
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-06-16 23:05 UTC by Ian Meyer
Modified: 2023-09-14 01:21 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2014-06-02 13:22:33 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

Description Ian Meyer 2010-06-16 23:05:06 UTC 
Description of problem:

Using http://gist.github.com/raw/441278/491762a02acddff9374c026fd3fe81221109e695/gistfile3.h on a RHEL 5.5 system exhibits the bad behavior.

Version-Release number of selected component (if applicable):
kernel 2.6.18-194.3.1.el5

How reproducible:
Always.

Steps to Reproduce:
1. Download and compile http://gist.github.com/raw/441278/491762a02acddff9374c026fd3fe81221109e695/gistfile3.h
2. Execute compiled binary

Alternatively with ruby:
1. ruby -e 'IO.select([File.open("/sys/block/hda/size")], nil, nil, nil)'

On a fixed system, that ruby call will return instantly, on a broken system, it will hang indefinitely.
  
Actual results:
➜  ~  ./blah hda 
fd = 3
selret = 0
FD_ISSET(3) is 0
time elapsed = 4.999650 seconds

Expected results:
fd = 3
selret = 1
FD_ISSET(3) is 1
time elapsed = 0.000024 seconds

Additional info:

This was fixed in commit 1af3557abdef34ee036a6de4cb79e24468544b8d of kernel 2.6.30
Comment 1 Matthew Kent 2010-06-16 23:10:09 UTC 
Seeing this on 2.6.18-164 as well, verified it's fixed in 2.6.30 on another server.
Comment 2 Oleksiy Kovyrin 2011-12-04 07:57:27 UTC 
I was wondering if there is any progress on this bug. We experience it too on our rhel5 servers and really need a solution that does not boil down to "do not call select() on /proc or /sys files".
Comment 3 RHEL Program Management 2014-03-07 13:54:43 UTC 
This bug/component is not included in scope for RHEL-5.11.0 which is the last RHEL5 minor release. This Bugzilla will soon be CLOSED as WONTFIX (at the end of RHEL5.11 development phase (Apr 22, 2014)). Please contact your account manager or support representative in case you need to escalate this bug.
Comment 4 Ian Meyer 2014-03-07 20:00:13 UTC 
Why is this going to be closed as WONTFIX? I'm not sure what other information I need to provide here per the email request of "needinfo".
Comment 5 RHEL Program Management 2014-06-02 13:22:33 UTC 
Thank you for submitting this request for inclusion in Red Hat Enterprise Linux 5. We've carefully evaluated the request, but are unable to include it in RHEL5 stream. If the issue is critical for your business, please provide additional business justification through the appropriate support channels (https://access.redhat.com/site/support).
Comment 6 Red Hat Bugzilla 2023-09-14 01:21:29 UTC 
The needinfo request[s] on this closed bug have been removed as they have been unresolved for 1000 days
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