Re: segfault on x86_64 (Fedora Core 2) 2.6.x
The segfault messages look benign - they are the implicit NULL checks within JVM. Did you see a hang or a crash (i.e. tomcat process is gone, segfaults in kernel log don't count, they are handled by JVM)? Is this on HT Xeon? I've heard 2.6.5 in FC2 is not stable (frequent hang) but 2.6.6 is Ok, looks like your case is different. I haven't got a chance to load FC2 on my machine yet. regards, -hui Marc Heckmann wrote: Hi, I am using j2sdk-1.4.2 on Fedora Core 2 x86_64. when starting tomcat v4.1.30 (haven't tried any other version), I get segfaults and my webapps do not run properly at all. This happens with either the 32 bit or native 64 bit versions of the SDK. I have tried on 2 separate machines with the same results. Here are some of the messages I get: java[4508]: segfault at 0008 rip 002a98544a78 rsp 007fbfffc1d0 error 4 java[4520]: segfault at 0008 rip 002a9845f3c2 rsp 4148bf20 error 4 The same thing happens with Sun's SDK. Kernel version 2.6.7-rc2-bk6 as well as 2.6.6. Kernel 2.4.27-rc5 does not show this behaviour. Anyone seen this before? Thanks in advance. -m -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: segfault on x86_64 (Fedora Core 2) 2.6.x
Radu-Adrian Popescu <[EMAIL PROTECTED]> writes: > The error codes come in groups of 1-4 at a time, and they're > alternate. > > What's causing this ? HotSpot uses SIGSEGV internally. It does on x86 too, but the x86 kernel doesn't have a segfault logger, so you don't get these messages there. IIRC there's no way to disable the x86_64 segfault logger without recompiling the kernel. > Oh and when is 1.4.2 64-bit final coming out :) ? In a few days, we're in the final testing stage. Juergen -- Juergen Kreileder, Blackdown Java-Linux Team http://www.blackdown.org/java-linux/java2-status/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: segfault on x86_64 (Fedora Core 2) 2.6.x
Marc Heckmann wrote: Hi, I am using j2sdk-1.4.2 on Fedora Core 2 x86_64. when starting tomcat v4.1.30 (haven't tried any other version), I get segfaults and my webapps do not run properly at all. This happens with either the 32 bit or native 64 bit versions of the SDK. I have tried on 2 separate machines with the same results. Here are some of the messages I get: java[4508]: segfault at 0008 rip 002a98544a78 rsp 007fbfffc1d0 error 4 java[4520]: segfault at 0008 rip 002a9845f3c2 rsp 4148bf20 error 4 The same thing happens with Sun's SDK. Kernel version 2.6.7-rc2-bk6 as well as 2.6.6. Kernel 2.4.27-rc5 does not show this behaviour. Anyone seen this before? Thanks in advance. I'm running FC2 x86_64 with Java(TM) 2 Runtime Environment, Standard Edition (build Blackdown-1.4.2-rc1) Java HotSpot(TM) 64-Bit Server VM (build Blackdown-1.4.2-rc1, mixed mode)> on kernel <2.6.5-1.358> and I get them segfaults too, with error codes 4 & 6. The applications seem to work just fine, though. Jun 9 20:05:04 rpopescu kernel: java[1673]: segfault at 0008 rip 002a985392a6 rsp 41f94790 error 4 Jun 9 21:35:28 rpopescu kernel: java[2883]: segfault at 4fe8 rip 57a619e5 rsp 7fe8 error 6 The error codes come in groups of 1-4 at a time, and they're alternate. What's causing this ? Oh and when is 1.4.2 64-bit final coming out :) ? Cheers, -- Radu-Adrian Popescu CSA, DBA, Developer Aldrapay MD Aldratech Ltd. +40213212243 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: segfault on x86_64 (Fedora Core 2) 2.6.x
Juergen Kreileder wrote: HotSpot uses SIGSEGV internally. It does on x86 too, but the x86 kernel doesn't have a segfault logger, so you don't get these messages there. IIRC there's no way to disable the x86_64 segfault logger without recompiling the kernel. Oh and when is 1.4.2 64-bit final coming out :) ? In a few days, we're in the final testing stage. Fabulous, thanks Juergen ! Keep up the excellent work guys! Regards, -- Radu-Adrian Popescu CSA, DBA, Developer Aldrapay MD Aldratech Ltd. +40213212243 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: segfault on x86_64 (Fedora Core 2) 2.6.x
On Wed, Jun 09, 2004 at 11:58:32PM -0700, Hui Huang wrote: > The segfault messages look benign - they are the implicit NULL checks > within JVM. But look at the following discussion, Andi Kleen one of the x86_64 kernel developers says that the kernel has been fixed not to log the messages if it is not a real segfault: http://bugme.osdl.org/show_bug.cgi?id=2839 But maybe they fixed 2.4 and forgot to do so for 2.6.x? It also seems to me that the Sun 1.4.2 JVM did not function correctly (1.5.0-beta for x86_64 did actually dump core.) in that the webapp was not functioning correctly. I will have to do more extensive tests using blackdown with my own code when I have a minute to confirm (or not) this. I will let you know. -m -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: segfault on x86_64 (Fedora Core 2) 2.6.x
Marc Heckmann <[EMAIL PROTECTED]> writes:
> On Wed, Jun 09, 2004 at 11:58:32PM -0700, Hui Huang wrote:
>> The segfault messages look benign - they are the implicit NULL
>> checks within JVM.
>
> But look at the following discussion, Andi Kleen one of the x86_64
> kernel developers says that the kernel has been fixed not to log the
> messages if it is not a real segfault:
>
> http://bugme.osdl.org/show_bug.cgi?id=2839
>
> But maybe they fixed 2.4 and forgot to do so for 2.6.x?
It looks like it's supposed to be fixed in 2.6 too. But a quick test
shows that it actually works the other way round, at least in 2.6.6:
Only catched segfaults get logged!
Here's a patch which fixed the problem for me;
--- arch/x86_64/mm/fault.c.orig 2004-06-10 19:51:45.0 +0200
+++ arch/x86_64/mm/fault.c 2004-06-10 20:38:38.0 +0200
@@ -210,11 +210,11 @@ static int is_errata93(struct pt_regs *r
int unhandled_signal(struct task_struct *tsk, int sig)
{
- /* Warn for strace, but not for gdb */
- if ((tsk->ptrace & (PT_PTRACED|PT_TRACESYSGOOD)) == PT_PTRACED)
- return 0;
- return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) ||
- (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL);
+ /* I'm not sure about PT_TRACESYSGOOD. Is gdb supposed
+ to use PTRACE_O_TRACESYSGOOD? Mine doesn't. */
+ return !(tsk->ptrace & PT_PTRACED) &&
+ ((tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) ||
+(tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL));
}
int page_fault_trace;
@@ -374,7 +374,7 @@ bad_area_nosemaphore:
(address >> 32))
return;
- if (exception_trace && !unhandled_signal(tsk, SIGSEGV)) {
+ if (exception_trace && unhandled_signal(tsk, SIGSEGV)) {
printk(KERN_INFO
"%s[%d]: segfault at %016lx rip %016lx rsp %016lx error %lx\n",
tsk->comm, tsk->pid, address, regs->rip,
> It also seems to me that the Sun 1.4.2 JVM did not function
> correctly (1.5.0-beta for x86_64 did actually dump core.) in that
> the webapp was not functioning correctly.
32-bit VMs should work OK (unless you use noexec32=all,on; only
Blackdown 1.4.2 works fine with that).
As for 64-bit VMs, please wait a few days: 1.4.2-fcs will fix quite a few
x86_64 specific bugs.
Juergen
--
Juergen Kreileder, Blackdown Java-Linux Team
http://www.blackdown.org/java-linux/java2-status/
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Help on JVM hang
Hi folks, I'm posting this, since I know I can get help only from this community. My application is a heavily multi-threaded java application which is runs in Linux with the following configuration OS - RH9 Kernel - 2.4.20-30.9smp glibc - glibc-2.3.2-27.9.7 JVM - SUN 1.4.2 My applications HANGS after runnning for some time. Do you any work arounds for this problem "Thread-11" prio=1 tid=0x6a920368 nid=0x999 runnable [6bc7b000..6bc7b854] at java.io.ExpiringCache.cleanup(ExpiringCache.java:94) at java.io.ExpiringCache.get(ExpiringCache.java:51) - locked <0x46e82cb0> (a java.io.ExpiringCache) at java.io.UnixFileSystem.canonicalize(UnixFileSystem.java:137) at java.io.File.getCanonicalPath(File.java:513) at java.io.FilePermission$1.run(FilePermission.java:218) at java.security.AccessController.doPrivileged(Native Method) at java.io.FilePermission.init(FilePermission.java:212) at java.io.FilePermission.(FilePermission.java:264) at java.lang.SecurityManager.checkRead(SecurityManager.java:863) at java.io.File.exists(File.java:678) I dont get this problem if I run with LD_ASSUME_KERNEL=2.2.5 setting. But the applications runs very slow( around 50% slower). Does anyone has come accross this problem ? Reg Veda
