Last night I thought of upgrading my Fedora 11 to Fedora 12.I went through Fedora Official website and came across a new tool called preupgrade.It went fine and so wanted to share it with you all.
Here we go...
In most cases, the simplest way to upgrade an existing Fedora installation is with the preupgrade tool. When a new version of Fedora is available, preupgrade downloads the packages necessary to upgrade your installation, and initiates the upgrade process.
Install preupgrade with your graphical package manager, or
type yum install preupgrade at the command line and press Enter.
To run preupgrade, type preupgrade at the command line and press Enter.
Note:
If the contents of your /etc/fedora-release file have been changed from the default, your Fedora installation may not be found when attempting an upgrade to Fedora 12.
You can relax some of the checks against this file by booting with the following boot command:
linux upgradeany
Use the linux upgradeany command if your Fedora installation was not given as an option to upgrade.
To perform an upgrade, select Perform an upgrade of an existing installation. Click Next when you are ready to begin your upgrade.
To re-install your system, select Perform a new Fedora installation and refer to Chapter 6, Installing on Intel® and AMD Systems for further instructions.
Friday, March 26, 2010
Understanding /proc/cpuinfo?
A hyperthreaded processor has the same number of function units as an older, non-hyperthreaded processor. It just has two execution contexts, so it can maybe achieve better function unit utilization by letting more than one program execute concurrently. On the other hand, if you're running two programs which compete for the same function units, there is no advantage at all to having both running "concurrently." When one is running, the other is necessarily waiting on the same function units.
A dual core processor literally has two times as many function units as a single-core processor, and can really run two programs concurrently, with no competition for function units.
A dual core processor is built so that both cores share the same level 2 cache. A dual processor (separate physical cpus) system differs in that each cpu will have its own level 2 cache. This may sound like an advantage, and in some situations it can be but in many cases new research and testing shows that the shared cache can be faster when the cpus are sharing the same or very similar tasks.
In general Hyperthreading is considered older technology and is no longer supported in newer cpus. Hyperthreading can provide a marginal (10%) for some server workloads like mysql, but dual core technology has essentially replaced hyperthreading in newer systems.
A dual core cpu running at 3.0Ghz should be faster then a dual cpu (separate core) system running at 3.0Ghz due to the ability to share the cache at higher bus speeds.
The examples below details how we determine what kind of cpu(s) are present.
The kernel data Linux exposes in /proc/cpuinfo will show each logical cpu with a unique processor number. A logical cpu can be a hyperthreading sibling, a shared core in a dual or quad core, or a separate physical cpu. We must look at the siblings, cpu cores and core id to tell the difference.
If the number of cores = the number of siblings for a given physical processor, then hyperthreading is OFF.
/bin/cat /proc/cpuinfo | /bin/egrep 'processor|model name|cache size|core|sibling|physical'
Example 1: Single processor, 1 core, no Hyperthreading
processor : 0
model name : AMD Duron(tm) processor
cache size : 64 KB
Example 2: Single processor, 1 core, Hyperthreading is enabled.
Notice how we have 2 siblings, but only 1 core. The physical cpu id is the same for both: 0.
processor : 0
model name : Intel(R) Pentium(R) 4 CPU 2.80GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
processor : 1
model name : Intel(R) Pentium(R) 4 CPU 2.80GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
Example 3. Single socket Quad Core
Notice how each processor has its own core id. The number of siblings matches the number of cores so there are no Hyperthreading siblings. Also notice the huge l2 cache - 6 MB. That makes sense though, when considering 4 cores share that l2 cache.
processor : 0
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
processor : 1
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 1
cpu cores : 4
processor : 2
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 2
cpu cores : 4
processor : 3
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 3
cpu cores : 4
Example 3a. Single socket Dual Core
Again, each processor has its own core so this is a dual core system.
processor : 0
model name : Intel(R) Pentium(R) D CPU 3.00GHz
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
processor : 1
model name : Intel(R) Pentium(R) D CPU 3.00GHz
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
Example 4. Dual Single core CPU, Hyperthreading ENABLED
This example shows that processer 0 and 2 share the same physical cpu and 1 and 3 share the same physical cpu. The number of siblings is twice the number of cores, which is another clue that this is a system with hyperthreading enabled.
processor : 0
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
processor : 1
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 1
processor : 2
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
processor : 3
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 1
Example 5. Dual CPU Dual Core No hyperthreading
Of the 5 examples this should be the most capable system processor-wise. There are a total of 4 cores; 2 cores in 2 separate socketed physical cpus. Each core shares the 4MB cache with its sibling core. The higher clock rate (3.0 Ghz vs 2.3Ghz) should offer slightly better performance than example 3.
processor : 0
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
processor : 1
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
processor : 2
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 2
processor : 3
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 3
siblings : 2
core id : 1
cpu cores : 2
A dual core processor literally has two times as many function units as a single-core processor, and can really run two programs concurrently, with no competition for function units.
A dual core processor is built so that both cores share the same level 2 cache. A dual processor (separate physical cpus) system differs in that each cpu will have its own level 2 cache. This may sound like an advantage, and in some situations it can be but in many cases new research and testing shows that the shared cache can be faster when the cpus are sharing the same or very similar tasks.
In general Hyperthreading is considered older technology and is no longer supported in newer cpus. Hyperthreading can provide a marginal (10%) for some server workloads like mysql, but dual core technology has essentially replaced hyperthreading in newer systems.
A dual core cpu running at 3.0Ghz should be faster then a dual cpu (separate core) system running at 3.0Ghz due to the ability to share the cache at higher bus speeds.
The examples below details how we determine what kind of cpu(s) are present.
The kernel data Linux exposes in /proc/cpuinfo will show each logical cpu with a unique processor number. A logical cpu can be a hyperthreading sibling, a shared core in a dual or quad core, or a separate physical cpu. We must look at the siblings, cpu cores and core id to tell the difference.
If the number of cores = the number of siblings for a given physical processor, then hyperthreading is OFF.
/bin/cat /proc/cpuinfo | /bin/egrep 'processor|model name|cache size|core|sibling|physical'
Example 1: Single processor, 1 core, no Hyperthreading
processor : 0
model name : AMD Duron(tm) processor
cache size : 64 KB
Example 2: Single processor, 1 core, Hyperthreading is enabled.
Notice how we have 2 siblings, but only 1 core. The physical cpu id is the same for both: 0.
processor : 0
model name : Intel(R) Pentium(R) 4 CPU 2.80GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
processor : 1
model name : Intel(R) Pentium(R) 4 CPU 2.80GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
Example 3. Single socket Quad Core
Notice how each processor has its own core id. The number of siblings matches the number of cores so there are no Hyperthreading siblings. Also notice the huge l2 cache - 6 MB. That makes sense though, when considering 4 cores share that l2 cache.
processor : 0
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
processor : 1
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 1
cpu cores : 4
processor : 2
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 2
cpu cores : 4
processor : 3
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 3
cpu cores : 4
Example 3a. Single socket Dual Core
Again, each processor has its own core so this is a dual core system.
processor : 0
model name : Intel(R) Pentium(R) D CPU 3.00GHz
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
processor : 1
model name : Intel(R) Pentium(R) D CPU 3.00GHz
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
Example 4. Dual Single core CPU, Hyperthreading ENABLED
This example shows that processer 0 and 2 share the same physical cpu and 1 and 3 share the same physical cpu. The number of siblings is twice the number of cores, which is another clue that this is a system with hyperthreading enabled.
processor : 0
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
processor : 1
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 1
processor : 2
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
processor : 3
model name : Intel(R) Xeon(TM) CPU 3.60GHz
cache size : 1024 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 1
Example 5. Dual CPU Dual Core No hyperthreading
Of the 5 examples this should be the most capable system processor-wise. There are a total of 4 cores; 2 cores in 2 separate socketed physical cpus. Each core shares the 4MB cache with its sibling core. The higher clock rate (3.0 Ghz vs 2.3Ghz) should offer slightly better performance than example 3.
processor : 0
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
processor : 1
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
processor : 2
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 3
siblings : 2
core id : 0
cpu cores : 2
processor : 3
model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz
cache size : 4096 KB
physical id : 3
siblings : 2
core id : 1
cpu cores : 2
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