Re: [PATCH] s390/oprofile: Remove deprecated create_workqueue

From: Hendrik Brueckner
Date: Fri Jun 17 2016 - 05:08:43 EST


On Tue, Jun 14, 2016 at 05:56:09PM +0200, Heiko Carstens wrote:
> On Tue, Jun 14, 2016 at 03:28:23PM +0200, Robert Richter wrote:
> > >
> > > Documentation/kernel-parameters.txt | 2 -
> > > arch/s390/oprofile/Makefile | 1 -
> > > arch/s390/oprofile/hwsampler.c | 1178 --------------------------------
> > > arch/s390/oprofile/hwsampler.h | 63 --
> > > arch/s390/oprofile/init.c | 489 -------------
> > > arch/s390/oprofile/op_counter.h | 21 -
> > > 6 files changed, 1754 deletions(-)
> >
> > Could you send the patch for review anyway?
>
> Yes, of course. I added it below, hope that's ok.
> [I did not yet add your Ack]
>
> From 74ab0aefe07573358cc6a0c462ddc62ccba4c0cf Mon Sep 17 00:00:00 2001
> From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> Date: Fri, 10 Jun 2016 10:40:06 +0200
> Subject: [PATCH] s390/oprofile: remove hardware sampler support
>
> Remove hardware sampler support from oprofile module.
>
> The oprofile user space utilty has been switched to use the kernel
> perf interface, for which we also provide hardware sampling support.
>
> In addition the hardware sampling support is also slightly broken: it
> supports only 16 bits for the pid and therefore would generate wrong
> results on machines which have a pid >64k.
>
> Also the pt_regs structure which was passed to oprofile common code
> cannot necessarily be used to generate sane backtraces, since the
> task(s) in question may run while the samples are fed to oprofile.
> So the result would be more or less random.
>
> However given that the only user space tools switched to the perf
> interface already four years ago the hardware sampler code seems to be
> unused code, and therefore it should be reasonable to remove it.
>
> The timer based oprofile support continues to work.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> ---
> Documentation/kernel-parameters.txt | 2 -
> arch/s390/oprofile/Makefile | 1 -
> arch/s390/oprofile/hwsampler.c | 1178 -----------------------------------
> arch/s390/oprofile/hwsampler.h | 63 --
> arch/s390/oprofile/init.c | 489 ---------------
> arch/s390/oprofile/op_counter.h | 21 -
> 6 files changed, 1754 deletions(-)
> delete mode 100644 arch/s390/oprofile/hwsampler.c
> delete mode 100644 arch/s390/oprofile/hwsampler.h
> delete mode 100644 arch/s390/oprofile/op_counter.h
>

Reviewed-by: Hendrik Brueckner <brueckner@xxxxxxxxxxxxxxxxxx>