OK jonathan,
I understand.
So, looking on right place now, i can see few locks and sometimes no locks
(just Mutex Hold). But I still have many threads in 100% LCK.
If I don't have a lot of locks, where is my problem ?
Running rickey c weisner's script a get:
(...)
25736
libc.so.1`_so_send+0x15
libjvm.so`__1cDhpiEsend6Fipcii_i_+0x67
libjvm.so`JVM_Send+0x32
libnet.so`Java_java_net_SocketOutputStream_socketWrite0+0x131
0xc3c098d3
10
25736
0xc3d2a33a
14
25736
libc.so.1`_write+0x15
libjvm.so`__1cDhpiFwrite6FipkvI_I_+0x5d
libjvm.so`JVM_Write+0x30
libjava.so`0xc8f7c04b
16
25736
libc.so.1`stat64+0x15
21
25736
libc.so.1`_write+0x15
libjvm.so`__1cDhpiFwrite6FipkvI_I_+0x5d
libjvm.so`JVM_Write+0x30
libjava.so`0xc8f80ce9
76
java 25736 kernel-level lock 1
java 25736 shuttle 6
java 25736 preempted 7
java 25736 user-level lock 511
java 25736 condition variable 748
Atenciosamente,
------------------------------------------------------------------
Kleyson Rios.
Gerência de Suporte Técnico
Analista de Suporte / Líder de Equipe
-----Mensagem original-----
De: Jonathan Adams [mailto:[EMAIL PROTECTED]
Enviada em: sexta-feira, 18 de abril de 2008 15:40
Para: Kleyson Rios
Cc: [email protected]
Assunto: Re: [dtrace-discuss] RES: Process in LCK / SLP (Please)
On Apr 18, 2008, at 1:03 PM, Kleyson Rios wrote:
> Hi przemol,
>
> Bellow output of plockstat for malloc and libumem. Both many locks.
> Why changing to libumem I didn't get less locks ?
>
You're looking at Mutex hold statistics, which don't mean a lot
(unless contention is caused by long hold times)
The important thing for multi-threaded performance is *contention*.
(Spinning and blocking) Those are the statistics you should be
looking at.
Both malloc and libumem use locks to protect their state; libumem
just uses many locks, in order to reduce contention.
Cheers,
- jonathan
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