/proc/sys/vm/swappiness is nice, but I want a knob that is per process like /proc/$PID/oom_adj. So that I can make certain processes less likely than others to have any of their pages swapped out. Unlike memlock(), this doesn’t prevent a program from being swapped out. And like nice, the user by default can’t make their programs less likely, but only more likely to get swapped. I think I had to call this /proc/$PID/swappiness_adj.
If I do watch cat /proc/sys/kernel/random/entropy_avail I see that my systems entropy slowly increases over time, until it reaches the 180-190 range at which point it drops down to around 120-130. The drops in entropy seem to occur about every twenty seconds. I observe this even when lsof says that no process has /dev/random or /dev/urandom open. What is draining away the entropy? Does the kernel need entropy as well, or maybe it is reprocessing the larger pool into a smaller, better quality pool?
On Linux 3.11.0-13-generic running on top of a dual socket Xeon X5650 hexa core board, htop shows different kworker threads. Sorted by names (I tweaked the result I am showing here a little bit to have the threads on core 2 before the ones on core 10), here is the result:
I’m seeing very high RX dropped packets in the output of ifconfig: Thousands of packets per second, an order of magnitude more than regular RX packets.
I know with mkdir I can do mkdir A B C D E F to create each directory. How do I create directories A-Z or 1-100 with out typing in each letter or number?
How or where does Linux determine the assignment of a network device? Specifically, wlan0 or wlan1 for wireless USB devices.
When I run chmod +w filename it doesn’t give write permission to other, it just gives write permission to user and group.
What sets the size of the tmpfs? (On my machine it resides in /dev/shm)
I can see its entry in /etc/fstab, but no notation of its size.
When checking with df -h, it seems to be half the size of the physical memory installed in the system.
Is this the default behavior?
I want to know whether there is any easier way to run a job every 25 minutes. In cronjob, if you specify the minute parameter as */25, it’ll run only on 25th and 50th minute of every hour
I have this message in dmesg log with linux 3.11.6-1 (2013-10-27) (debian version).