Bug 130543 - rdtsc opcode invalid on some cpu (trivial fix)
Summary: rdtsc opcode invalid on some cpu (trivial fix)
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: rpm
Version: 3
Hardware: i386
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Jeff Johnson
QA Contact: Mike McLean
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2004-08-21 14:27 UTC by Eric Thomas
Modified: 2007-11-30 22:10 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2004-08-21 14:50:10 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Eric Thomas 2004-08-21 14:27:30 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510

Description of problem:
I know that support for 486 cpus is dropped but the fix is so trivial
that It would be a shame to do nothing.
Some rpm binaries cannot work on those cpus because of the use of the
rdtsc opcode.
As the opcode is specific to intel, it is already enclosed by a #if
defined(__386__) in rpmio/rpmsw.c
Replacing it by (or adding) a __686__ test could *at least* allow a
rebuild of the package without having to edit the source file first.

If any cpu-type identification could be done at runtime to allow, or
not, to use the rdtsc opcode, then it would be really great !

The bug is opened for fc3test1 because it would be nice to fix it
before fc3 release but the bug last from fc2 at least.


Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1.rebuild of the rpm package for 486 needs source file modification
first, whereas it could avoided if fixed
2.
3.
    

Additional info:

Comment 1 Jeff Johnson 2004-08-21 14:50:10 UTC
rdtsc is used to eliminate endless gettimeofday calls
in strace logs.

Sure the "fix" to use rpm on i486 is trivial. A run time
test is possible as well.

However, the vast majority of rpm users are not "i486".
Edit the source file if you need rpm on i486.

Comment 2 Eric Thomas 2004-08-21 21:54:24 UTC
Replacing __i386__ by __586__ would have cost you less time than
answering me why you won't do it :-(
And no one from "the vast majority" would have suffered from it.



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