This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCHv2] powerpc: Fix tabort usage in syscalls
- From: "Tulio Magno Quites Machado Filho" <tuliom at linux dot vnet dot ibm dot com>
- To: "Paul E. Murphy" <murphyp at linux dot vnet dot ibm dot com>
- Cc: "libc-alpha\ at sourceware dot org" <libc-alpha at sourceware dot org>
- Cc:
- Date: Tue, 25 Aug 2015 13:30:39 -0300
- Subject: Re: [PATCHv2] powerpc: Fix tabort usage in syscalls
- Authentication-results: sourceware.org; auth=none
- References: <55D77E55 dot 4010801 at linux dot vnet dot ibm dot com>
"Paul E. Murphy" <murphyp@linux.vnet.ibm.com> writes:
> Fix usage of tabort in generated syscalls. r0 has special meaning
> when used with this instruction, thus it will not generate
> persistent errors, nor return an error code. This mitigates poor
> CPU usage when performing elided critical sections.
>
> Additionally, transactions should be aborted when entering a user
> invoked syscall. Otherwise the results of the transaction may be
> undefined.
>
> 2015-08-03 Paul E. Murphy <murphyp@linux.vnet.ibm.com>
>
> * sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION): Use
> register other than r0 for tabort, it has special meaning.
> * sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION): Likewise
> * sysdeps/unix.sysv/linux/powerpc/syscall.S (syscall): Abort
> transaction before starting syscall.
LGTM.
I'm pushing it.
Thanks!
--
Tulio Magno