Re: [PATCH] perf/core: fast breakpoint modification via _IOC_MODIFY_BREAKPOINT

Arnaldo Carvalho de Melo
2017-11-06T15:03:55Z

Em Mon, Nov 06, 2017 at 07:00:29AM -0800, Milind Chabbi escreveu:
> Hi Jirka,
>
> I see the tabs in my sent email, do you have suggestions on how best to
> send this patch so that the tabs are preserved by the email client?

Documentation/process/email-clients.rst

- Arnaldo

> Can anybody else also check if they received with/without tabs?
>
> release_bp_slot/reserve_bp_slot majic is not necessary since
> _IOC_MODIFY_BREAKPOINT ioctl modifies an already registered breakpoint
> without affecting the count of breakpoints active.
>
> -Milind
>
> On Mon, Nov 6, 2017 at 1:23 AM, Jiri Olsa <jolsa@redhat.com> wrote:
>
> > On Sun, Nov 05, 2017 at 02:35:34PM -0800, Milind Chabbi wrote:
> >
> > SNIP
> >
> > > +static int _perf_event_modify_breakpoint(struct perf_event *bp,
> > > + struct perf_event_attr *attr)
> > > +{
> > > + u64 old_addr = bp->attr.bp_addr;
> > > + u64 old_len = bp->attr.bp_len;
> > > + int old_type = bp->attr.bp_type;
> > > + int err = 0;
> > > +
> > > + _perf_event_disable(bp);
> > > +
> > > + bp->attr.bp_addr = attr->bp_addr;
> > > + bp->attr.bp_type = attr->bp_type;
> > > + bp->attr.bp_len = attr->bp_len;
> > > +
> > > + if (attr->disabled)
> > > + goto end;
> > > +
> > > + err = validate_hw_breakpoint(bp);
> >
> > thre patch is mangled.. seems like you've lost all your tabs somehow
> >
> > anyway, should you also do the release_bp_slot/reserve_bp_slot
> > magic to keep the slot accounting corrent?
> >
> > jirka
> >