Showing entries 1 to 7
Displaying posts with tag: malloc (reset)
One last bit of evil….

You can store things for later! drizzle> select libtcc("#include <string.h>\n#include <stdlib.h>\nint foo(char* s) { char *a= malloc(1000); return snprintf(s, 100, \"%p\", a); }") as RESULT;

+-----------+
| RESULT    |
+-----------+
| 0x199c610 |
+-----------+
1 row in set (0 sec)

drizzle> select libtcc("#include <string.h>\n#include <stdlib.h>\nint foo(char* s) { char *a= 0x199c610; strcpy(a, \"Hello World!\"); strcpy(s,\"done\"); return strlen(s); }") as result;

+--------+
| result |
+--------+
| done   |
+--------+
1 row in set (0.01 sec)

drizzle> select libtcc("#include <string.h>\n#include <stdlib.h>\nint foo(char* s) { char *a= 0x199c610; strcpy(s, a); return strlen(s); }") as result;

+--------------+
| result       |
+--------------+
| Hello World! | …
[Read more]
MySQL 5.1 Memory Allocator Bake-Off

After getting sysbench running properly with a scalable memory allocator (see last post), I can now return to what I was originally testing - what memory allocator is best for the 5.1 server (mysqld).

This stems out of studies I have made of some patches that have been released by Google. You can read about the work Google has been doing here.

I decided I wanted to test a number of configurations based on the MySQL community source, 5.1.28-rc, namely:

  • The baseline - no Google SMP patch, default memory allocator (5.1.28-rc)
  • With Google SMP patch, mem0pool enabled, no custom malloc (pool)
  • With Google SMP patch, mem0pool enabled, linked with mtmalloc (pool-mtmalloc)
  • With Google SMP patch, mem0pool disabled, linked with tcmalloc (TCMalloc)
  • With Google SMP patch, mem0pool …
[Read more]
MySQL 5.1 Memory Allocator Bake-Off

After getting sysbench running properly with a scalable memory allocator (see last post), I can now return to what I was originally testing - what memory allocator is best for the 5.1 server (mysqld).

This stems out of studies I have made of some patches that have been released by Google. You can read about the work Google has been doing here.

I decided I wanted to test a number of configurations based on the MySQL community source, 5.1.28-rc, namely:

  • The baseline - no Google SMP patch, default memory allocator (5.1.28-rc)
  • With Google SMP patch, mem0pool enabled, no custom malloc (pool)
  • With Google SMP patch, mem0pool enabled, linked with mtmalloc (pool-mtmalloc)
  • With Google SMP patch, mem0pool disabled, linked with tcmalloc (TCMalloc)
  • With Google SMP patch, mem0pool …
[Read more]
MySQL 5.1 Memory Allocator Bake-Off

After getting sysbench running properly with a scalable memory allocator (see last post), I can now return to what I was originally testing - what memory allocator is best for the 5.1 server (mysqld).

This stems out of studies I have made of some patches that have been released by Google. You can read about the work Google has been doing here.

I decided I wanted to test a number of configurations based on the MySQL community source, 5.1.28-rc, namely:

  • The baseline - no Google SMP patch, default memory allocator (5.1.28-rc)
  • With Google SMP patch, mem0pool enabled, no custom malloc (pool)
  • With Google SMP patch, mem0pool enabled, linked with mtmalloc (pool-mtmalloc)
  • With Google SMP patch, mem0pool disabled, linked with tcmalloc (TCMalloc)
  • With Google SMP patch, mem0pool …
[Read more]
Scalability and Stability for SysBench on Solaris

My mind is playing "Suffering Succotash..."

I have been working on MySQL performance for a while now, and the team I am in have discovered that SysBench could do with a couple of tweaks for Solaris.

Sidebar - sysbench is a simple "OLTP" benchmark which can test multiple databases, including MySQL. Find out all about it here , but go to the download page to get the latest version.

To simulate multiple users sending requests to a database, sysbench uses multiple threads. This leads to two issues we have identified with SysBench on Solaris, namely:

  • The implementation of random() is explicitly identified as unsafe in multi-threaded applications on Solaris. My team has found this is a real issue, with occasional core-dumps happening to our …
[Read more]
Scalability and Stability for SysBench on Solaris

My mind is playing "Suffering Succotash..."

I have been working on MySQL performance for a while now, and the team I am in have discovered that SysBench could do with a couple of tweaks for Solaris.

Sidebar - sysbench is a simple "OLTP" benchmark which can test multiple databases, including MySQL. Find out all about it here , but go to the download page to get the latest version.

To simulate multiple users sending requests to a database, sysbench uses multiple threads. This leads to two issues we have identified with SysBench on Solaris, namely:

  • The implementation of random() is explicitly identified as unsafe in multi-threaded applications on Solaris. My team has found this is a real issue, with occasional core-dumps happening to our …
[Read more]
Scalability and Stability for SysBench on Solaris

My mind is playing "Suffering Succotash..."

I have been working on MySQL performance for a while now, and the team I am in have discovered that SysBench could do with a couple of tweaks for Solaris.

Sidebar - sysbench is a simple "OLTP" benchmark which can test multiple databases, including MySQL. Find out all about it here , but go to the download page to get the latest version.

To simulate multiple users sending requests to a database, sysbench uses multiple threads. This leads to two issues we have identified with SysBench on Solaris, namely:

  • The implementation of random() is explicitly identified as unsafe in multi-threaded applications on Solaris. My team has found this is a real issue, with occasional core-dumps happening to our …
[Read more]
Showing entries 1 to 7