Bug 51771 (acjohnson)
Summary: | slow and sporadic hard drive write performance on ivy bridge (Toshiba L840 Core i7-3612QM) | ||
---|---|---|---|
Product: | IO/Storage | Reporter: | Aaron Johnson (acjohnson) |
Component: | Other | Assignee: | io_other |
Status: | RESOLVED INSUFFICIENT_DATA | ||
Severity: | high | CC: | alan |
Priority: | P1 | ||
Hardware: | All | ||
OS: | Linux | ||
URL: | https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1090715 | ||
Kernel Version: | 3.7.0 | Subsystem: | |
Regression: | Yes | Bisected commit-id: | |
Attachments: | dmesg output during write speed issues |
Description
Aaron Johnson
2012-12-18 01:47:52 UTC
Update: I am able to get excellent write performance when running the Ubuntu mainline kernel version 3.7-rc4-raring located here: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.7-rc4-raring/ Good write speed tests: acjohnson@Satellite-L840:~$ dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 83886080 bytes (84 MB) copied, 0.128812 s, 651 MB/s acjohnson@Satellite-L840:~$ dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 83886080 bytes (84 MB) copied, 0.444917 s, 189 MB/s acjohnson@Satellite-L840:~$ dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 83886080 bytes (84 MB) copied, 0.13095 s, 641 MB/s acjohnson@Satellite-L840:~$ dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 83886080 bytes (84 MB) copied, 0.13606 s, 617 MB/s acjohnson@Satellite-L840:~$ dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 83886080 bytes (84 MB) copied, 0.137573 s, 610 MB/s acjohnson@Satellite-L840:~$ dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 83886080 bytes (84 MB) copied, 0.373419 s, 225 MB/s Actually the stability of my L840 is better with this kernel than any other version I have tested so far but with one exception which is suspend causes lockups. I believe the lockup consistently occurs on the third attempt to go into suspend and it consistently locks up before actually going into suspend. I still would like to get to the bottom of the write performance bug though. Why is the write performance so much better in the rc versions of linux 3.7 compared to the final release and even 3.7.1? Without knowing what configuration differences there are between the kernels it's impossible to tell. It's certainly very interesting that there is a difference, and a starting point would be to compare - the dmesg of the two - the modules loaded - the kernel build configuration options. - any boot options being used Update- So I never really got to the bottom of why this is happening on the 32-bit pae 3.7 kernel... I decided to install 64-bit ubuntu raring (13.04), and guess what, it works flawlessly. So apparently 32-bit kernels on new hardware is a bad idea, which I should have known I suppose, but it's too bad because there are a few third party applications that I am having a hard time with now because they don't properly support 64-bit linux. I am happy to report that ubuntu raring 64-bit runs exceptionally good on my Toshiba L840 right out of the box, even with the stock kernel. No hard drive performance issues, and no suspend lock-ups either ;) |