RFR(xxs): 8210314: [aix] NMT does not show "Safepoint" memory type
matthias.baesken at sap.com
Mon Sep 3 10:29:51 UTC 2018
Hi Thomas, looks good to me ( not a Reviewer however).
One other small difference I noticed when comparing AIX to other UNIX implementations (e.g. linux / bsd ) :
In perfMemory_aix.cpp / mmap_create_shared and mmap_attach_shared we call
While in perfMemory_linux.cpp (bsd and solaris as well) we call
Is there really a need for different call on AIX ?
And the z GC code base ( jdk/src/hotspot/os_cpu/linux_x86/gc/z/) contains also a couple of mmap calls , wonder where those are recorded .
Best regards, Matthias
> -----Original Message-----
> From: ppc-aix-port-dev <ppc-aix-port-dev-bounces at openjdk.java.net> On
> Behalf Of Thomas Stüfe
> Sent: Montag, 3. September 2018 11:46
> To: Hotspot dev runtime <hotspot-runtime-dev at openjdk.java.net>; ppc-
> aix-port-dev at openjdk.java.net
> Subject: RFR(xxs): 8210314: [aix] NMT does not show "Safepoint" memory
> Hi all,
> may I please have reviews for this small, AIX-only change.
> cr: http://cr.openjdk.java.net/~stuefe/webrevs/8210314-aix-NMT-does-
> bug: https://bugs.openjdk.java.net/browse/JDK-8210314
> On AIX, we have our own initialization for the safepoint mechanism. We
> missed registering the polling page with NMT, which the generic code
> path did. This patch adds that.
> Side note:
> We are different for two reasons. One, on ppc we use per default
> SIGTRAP for safepoint signalling, which can be switched off though.
> Second, on AIX, we cannot use os::reserve_memory() to obtain a polling
> page since that memory may not protectable (if it uses sysV shmat).
> Hence, the AIX specific coding.
> Best Regards, Thomas
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