-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 14/04/13 16:58, Michal Hocko wrote: > On Fri 12-04-13 14:38:00, Ivan Danov wrote: >> On 12/04/13 13:11, Michal Hocko wrote: >>> On Fri 12-04-13 12:49:30, Ivan Danov wrote: >>>> $ cat /proc/sys/vm/swappiness >>>> 60 >>> OK, thanks for confirming this. It is really strange that we do not swap >>> almost at all, then. >>>> I have increased my swap partition from nearly 2GB to around 16GB, >>>> but the problem remains. >>> Increasing the swap partition will not help much as it almost unused >>> with 2G already (at least last data shown that). >>> >>>> Here I attach the logs for the larger swap partition. I use a MATLAB >>>> script to simulate the problem, but it also works in Octave: >>>> X = ones(100000,10000); >>> AFAIU this will create a matrix with 10^9 elements and initialize them >>> to 1. I am not familiar with octave but do you happen to know what is >>> the data type used for the element? 8B? It would be also interesting to >>> know how is the matrix organized and initialized. Does it fit into >>> memory at all? >> Yes, 8B each, so it will be almost 8GB and it should fit into the >> memory. > > It won't fit in because kernel and other processes consume some memory > as well. So you have to swap. > >> I don't know details how it actually works, but if it cannot >> create the matrix, MATLAB complains about that. Since it starts >> complaining even after 2000 more in the second dimension, maybe it >> needs the RAM to create it all. However on the desktop machine, both >> RAM and swap are being used (quite a lot of them both). > > How much you swap depends on vm.swappiness. I would suggest increasing > the value if your workload is really so anononymous memory based. > Otherwise a lot of file pages are reclaimed which can lead to problems > you are seeing. > >>>> I have tried to simulate the problem on a desktop installation with >>>> 4GB of RAM, 10GB of swap partition, installed Ubuntu Lucid and then >>>> upgraded to 12.04, the problem isn't there, but the input is still >>>> quite choppy during the load. After the script finishes, everything >>>> looks fine. For the desktop installation the hard drive is not an >>>> SSD hard drive. >>> What is the kernel version used here? >> $ uname -a >> Linux ivan 3.2.0-40-generic #64-Ubuntu SMP Mon Mar 25 21:22:10 UTC >> 2013 x86_64 x86_64 x86_64 GNU/Linux > > Is there any chance you could test with the latest vanilla kernel and > Mel's patches from https://lkml.org/lkml/2013/4/11/516 on top? Sorry for the late comeback, I've been quite busy these days. I will try to compile the kernel in the weekend. However, I will do kernel compiling for first time, so maybe it could take me some time. Btw I have upgraded to Ubuntu 13.04, so my kernel now is: $ uname -a Linux ivan 3.8.0-19-generic #30-Ubuntu SMP Wed May 1 16:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux The problem is still there. > > [...] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJRkldrAAoJEJ8e6XRVH9TGgAIIAI7hw+YWhtiZ3LAr4SOQRvce xkRcSFUjmhW3FCSm5TERtUY6Ney3hJ9NU7I4yA56WGwOf2E6GnNkG0plewNMsWrM 4ZCFevsm1MoGP5576PUm8F0FF/0EfpFRLLwNNB7dDYDsXdmG8KlOYjlEB5H31lrR Ycx155ZvUgVUQXNg0tthaPoy8Qaw5sGI062d9tRA4f45fh7KFhX58HVHKT+L6LtV caLXwdH5Wkzi+Xshl6h8BGnB57fjQCDCEdltR3f1ddbUnh5kjvXKLGUWvuut7Ish vkbOTfSBbjOPtQly6DJ/xxS8HbSIsdDU4ecfWHGztl6r1lteFJDiqFA+bPsBszU= =oULy -----END PGP SIGNATURE----- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>