Messages in this thread | | | Date | Fri, 31 Mar 2006 11:48:51 +0200 | From | Jakob Oestergaard <> | Subject | NFS client (10x) performance regression 2.6.14.7 -> 2.6.15 |
| |
Hi guys,
I just found out... Installed 2.6.16.1 (32-bit) on a spanking new dual opteron 275 (dual-core) machine, and saw that my link jobs were taking ages.
I narrowed it down a bit - these are the kernels I have tested: 2.6.13.5: Good 2.6.14.7: Good 2.6.15: Poor 2.6.15.7: Poor 2.6.16.1: Poor
Sequential NFS I/O is good on all kernels. Only "ld" shows the problem.
On 2.6.14.7, I can run a large link job creating a 60 MB executable in 15.6 seconds wall-clock time.
On 2.6.15, the same link job takes 2 minutes 28 seconds.
This is almost 10 *times* longer.
Testing with tiobench, I can see no notable difference between the kernels (!) It seems that this is very specific to ld. I am using GNU ld version 2.15.
The NFS client mounts the working directory using NFS v3 over UDP with default (32k) rsize/wsize.
Since this machine is not in production yet, I can experiment with kernel patches on it - I would like to try and narrow this down even further - any suggestions as to which patches to exclude/include will be greatly appreciated.
Note; I did double-check all the common problems (ethernet problems, mount options, ...).
--
/ jakob
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |