Subject: Re: [PATCH 1/3] selftests/powerpc: Standardise TM calls

From: Anshuman Khandual <[email-masked]>
Date: Wed, 02 Dec 2015 10:11:27 +0530

On 12/02/2015 09:10 AM, Michael Ellerman wrote:
> On Tue, 2015-12-01 at 13:38 +0530, Anshuman Khandual wrote:
>> > On 12/01/2015 10:38 AM, Rashmica Gupta wrote:
>>> > > Currently tbegin, tend etc are written as opcodes or asm instructions. So
>>> > > standardise these to asm instructions.
>> > 
>> > I think the asm instructions can be used with only newer versions of GCC.
>> > But not sure, does it work with the older gcc as well ?
> No they don't work with all versions of GCC.
> 
> The HTM instructions were added in 4.9 AFAICS, but also backported to 4.8. That
> seems old enough to me.
> 
> Also we have another test (tm-syscall) which is already using the tbegin
> instruction, and no one has complained, so I don't think anyone is trying to
> build the selftests with really old compilers.

Its only a concern if you try to build these self tests on some older distro.
But then some other self tests dont build there because of lack of newer
compiler options. Its generic problem not something specific to this test.