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Re: [SYSTEMTAP/PATCH 0/4] RT aware systemtap patch set
- From: Josh Stone <jistone at redhat dot com>
- To: Santosh Shukla <sshukla at mvista dot com>
- Cc: systemtap at sourceware dot org
- Date: Mon, 15 Sep 2014 09:22:49 -0700
- Subject: Re: [SYSTEMTAP/PATCH 0/4] RT aware systemtap patch set
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- References: <1410246499-6938-1-git-send-email-sshukla at mvista dot com> <CAAyOgsYpSz3MFe7gOVFjorN=gYuu_2tLf5DAG0dUwhJGx7r2qw at mail dot gmail dot com> <5416F410 dot 7090009 at redhat dot com> <CAAyOgsaVorsyDhAMdsfOQ1tR0H5m-ceM6Hz2T530SkzEty9Bhg at mail dot gmail dot com>
Hi,
On 09/15/2014 08:41 AM, Santosh Shukla wrote:
> first wanted to get raw_locking specific to get into stap.
One ugly aspect of this is that we try to maintain compatibility with
older platforms too. It looks like raw_spin_lock didn't come into the
kernel until 2.6.33, which doesn't even cover RHEL6. If possible we try
to keep things running all the way back to RHEL4 (though see my earlier
RFC about dropping that).
That said, we can get away with new interfaces in some cases. e.g. I
believe stp_utrace.c and task_finder2.c can only be used on 3.x kernels.
But anything that's more generic, like addr-map.c, will need some kind
of wrapper or compat #define added to let it work on older kernels too.
Maybe just #define raw_spin_lock spin_lock, etc.
Josh