weird memory use since grsecurity-2.2.0-2.6.32.15

[adren]

I've given the new grsec (version 2.2.0) a try but since the last reboot (15 hours ago), I notice a very strange and much different use of my RAM compared to grsecurity-2.1.14 for the exact same kernel (2.6.32.15):

the slab_cache, buffers and cache are used much less with the new config than before

n.b.: I have 8GB of RAM and running Debian unstable arch amd64

since an image is worth a thousand words:
http://adren.org/~cyril/grsec2.2_mem.png

the machine rebooted at 8:30 this morning and one can clearly see the difference since then with all this unused memory (almost 5GB of RAM) which was never the case before

[PaX Team]

the machine rebooted at 8:30 this morning and one can clearly see the difference since then with all this unused memory (almost 5GB of RAM) which was never the case before

what's dmesg|grep Memory say?

[adren]

the machine rebooted at 8:30 this morning and one can clearly see the difference since then with all this unused memory (almost 5GB of RAM) which was never the case before

what's dmesg|grep Memory say?

Code: Select all

adren:~# dmesg|grep Memory
[    0.000000] Memory: 7986160k/9437184k available (4416k kernel code, 1180484k absent, 269624k reserved, 456k data, 400k init)


BTW, I've also upgraded to grsecurity-2.2.0-2.6.33.6-201007070906

[PaX Team]

Code: Select all

adren:~# dmesg|grep Memory
[    0.000000] Memory: 7986160k/9437184k available (4416k kernel code, 1180484k absent, 269624k reserved, 456k data, 400k init)

BTW, I've also upgraded to grsecurity-2.2.0-2.6.33.6-201007070906

hmm, nothing unusual in there... can you tell us how the machine behaves since? still not all memory used?

[adren]

hmm, nothing unusual in there... can you tell us how the machine behaves since? still not all memory used?

well, after few hours, all the memory seems to be used as it was before but I couldn't really tell if it's a normal behavior of the vanilla kernel or something that could be attributed to grsec

the other reason why I looked into the memory and how the machine was working in details was that I noticed some huge slowness of video player (both vlc and mplayer) when viewing big video file (> 4GB avi)
as if there was some deter going on (but I only have GRKERNSEC_BRUTE and GRKERNSEC_HARDEN_PTRACE which doesn't seem to be involved)


well, then I guess that puts an end to this weirdness (or else I'll have to do a bit more testing and comparing with stock kernel)