How to list interesting info about your cpu in linux

cat /proc/cpuinfo

example output:

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 26
model name    : Intel(R) Core(TM) i7 CPU         930  @ 2.80GHz
stepping    : 5
cpu MHz        : 1600.000
cache size    : 8192 KB
physical id    : 0
siblings    : 8
core id        : 0
cpu cores    : 4
apicid        : 0
initial apicid    : 0
fpu        : yes
fpu_exception    : yes
cpuid level    : 11
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm ida tpr_shadow vnmi flexpriority ept vpid
bogomips    : 5612.15
clflush size    : 64
cache_alignment    : 64
address sizes    : 36 bits physical, 48 bits virtual
power management:

processor    : 1
vendor_id    : GenuineIntel
cpu family    : 6

... etc

How to clear memory caches in ubuntu

While performance testing some mysql queries in ubuntu I came across the old problem that even after restarting mysql to clear its own buffers, the OS caches speed up consecutive runs of the same query. In order to get consistent results you need to flush both the mysql buffers and the native OS buffers.

Flushing the mysql buffers is as easy as restarting mysql ("sudo service mysql restart" in Maverick). Flushing the OS buffers is also dead easy:

sudo sh -c "sync; echo 3 > /proc/sys/vm/drop_caches"

I have system-monitor gauges on my taskbar showing cpu, memory and disk activity, and its a beautiful thing to see the cache suddenly get wiped :)