Tagged Questions

2
votes
1answer
397 views

Linux disk I/O performance issue — what config options to look at?

We discovered an I/O related performance problem when using the default SLES11 SP2 kernel. Our same application on the same hardware had no issue with (the admittedly ancient SLES9 SP3). We had a ...
1
vote
0answers
144 views

Perform test of aes-ni and aes module in linux kernel

Since both aes-ni and aes module are available in linux kernel , how can I give it a performance test , to decide which one's faster ?
3
votes
0answers
53 views

Timescales of any task in linux kernel?

I am studying how Linux kernel works and getting interested in the timescale of anything that happens in the kernel. Of course I know it depends on the HW, but would like to get an example. For ...
7
votes
3answers
3k views

Why is kworker consuming so many resources on Linux 3.0.0-12-server?

Last Friday I upgraded my Ubuntu server to 11.10, which now runs with a 3.0.0-12-server kernel. Since then the overall performance has dropped dramatically. Before the upgrade the system load was ...
8
votes
4answers
3k views

Use of O_DIRECT on Linux

If this question is too programmer oriented, let me know. I wonder if there are people familiar with the O_DIRECT flag for the open() system call on Linux 2.6? Linus disparages its use, however high ...
13
votes
2answers
3k views

Why does high disk I/O reduce system responsiveness/performance?

I never quite understood why high disk I/O slowed the system so much. It's strange to me because I would expect the slow-down to affect only those processes dependent on the hard/optical drive data, ...
8
votes
1answer
844 views

What's the progress regarding improving system performance/responsiveness during high disk I/O?

Whenever there is high disk I/O, the system tends to be much slower and less responsive than usual. What's the progress on Linux kernel regarding this? Is this problem actively being worked on?
9
votes
1answer
3k views

How can I configure cgroups to fairly share resources between users?

There used to be a kernel config option called sched_user or similar under cgroups. This allowed (to my knowledge) all users to fairly share system resources. In 2.6.35 it is not available. Is there a ...
3
votes
2answers
473 views

Does the Linux PreemptRT patch benefit desktop users?

Does the PREEMPT_RT patch (real-time kernel) have any benefit for regular desktop users?
8
votes
2answers
1k views

Heavy write activity on SSD nukes system performance

I've noticed that when I do heavy write applications, the whole system slows down. To test this further I ran this to do a (relatively) low-CPU, high disk activity: john -incremental > file_on_SSD ...
24
votes
12answers
2k views

How can I tweak my Linux desktop to be more responsive?

I have the experience that Linux works fine until the physical memory is exhausted. As soon as swap space is used the performance is severely degraded and the GUI becomes unresponsive. This problem ...