RFR (S) 8217879: hs_err should print more instructions in hex dump

[Thomas Stüfe]

I think this probing is not needed anymorewith 8217994, or?

On Wed, Jan 30, 2019 at 12:21 PM Schmidt, Lutz <lutz.schmidt at sap.com> wrote:

> Hi,
>
> is it really necessary to probe each and every byte in the range?
>  1) is_readable_pointer() tests four subsequent bytes. That suggests a
> stride of +/-4.
>  2) Assume a and b are two addresses on the same page. Are there platforms
> where a is accessible and b is not?
>
> If the answer to 2) is yes, then os::is_readable_range(const void* from,
> const void* to) needs to be fixed. Otherwise, at most one
> is_readable_pointer() call per page is necessary.
>
> Thanks for considering!
> Lutz
>
> On 29.01.19, 18:48, "hotspot-dev on behalf of Thomas Stüfe" <
> hotspot-dev-bounces at openjdk.java.net on behalf of thomas.stuefe at gmail.com>
> wrote:
>
>     On Tue, Jan 29, 2019 at 6:33 PM Aleksey Shipilev <shade at redhat.com>
> wrote:
>
>     > On 1/29/19 6:27 PM, Thomas Stüfe wrote:
>     > > On Tue, Jan 29, 2019 at 6:12 PM Aleksey Shipilev <shade at redhat.com
>     > <mailto:shade at redhat.com>> wrote:
>     > >
>     > >     On 1/29/19 5:34 PM, Thomas Stüfe wrote:
>     > >     > Even better. No need to store those bytes on the first leg.
>     > >
>     > >     This would be webrev.05:
>     > >       http://cr.openjdk.java.net/~shade/8217879/webrev.05/
>     > >
>     > > Looks fine. You could move calculation of low/high out of the loops
>     > though.
>     > > If you want to go with this one, I do not need another webrev.
>     >
>     > You cannot that easily? Having calculation is the loop guarantees
> low/high
>     > are definitely readable.
>     > You can do this outside the loop, with +1/-1 to delta, but that sets
> us up
>     > for the off-by-one errors...
>     >
>     >
>     Oh, okay. This is fine to me then.
>
>     ..Thomas
>
>
>
>     > -Aleksey
>     >
>     >
>
>
>