On Mon, 7 Mar 2016 21:20:18 +0100 Damjan Georgievski <gdamjan@xxxxxxxxx> wrote: > >>> The free command gets its information from /proc/meminfo. > >>> Performance-wise, it doesn't really matter if a few additional lines > >>> need to be parsed. > >> > >> Hello, > >> Thank you Florian. Actually, I already knew it's the same, I just > >> thought that he could use the free command instead of parsing it > >> himself. You're right. Performance-wise, it's pretty much the same. > >> > > > > Sorry, I didn't express myself properly. I didn't mean to criticize > > free. What I meant to say was that the time it takes to parse > > /proc/meminfo or free is negligible. It doesn't need to be any more > > efficient. free parses /proc/meminfo. libgtop parses /proc/meminfo. > > Querying the information probably takes much more time than parsing it. > > > > Your suggestion to use free may indeed be useful if the original poster > > wants parsing to be slightly simpler and does not mind the additional > > dependency. My impression was that they considered parsing to be too > > inefficient. > > there's also `sysinfo(2)` ah, thank you! and now that i found (or rather, thought about it) the source for /proc/meminfo [0] i can see that it uses sysinfo too. but sadly the cached size is not in sysinfo. then i tried to do what /proc/stat [1] does and after googling learned some facts: - you can't use "kernel-space" functions in "user-space" apps - so i cant use all the same functions as /proc/stat uses - you can't create new "syscall" functions in a kernel module - so i can't "export/map" those "kernel-space" functions to be used in my "user-space" app so it seems the only way to get deeper than /proc/stat would be to add new "syscalls" to the linux kernel? (for functions like for_each_possible_cpu and kcpustat_cpu) i'm just a webmonkey, so ill stick to /proc for now :D (i cant notice my daemon in cpu usage yet, so not really a "problem") Cheers Andre Schmidt [0] https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/fs/proc/meminfo.c [1] https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/fs/proc/stat.c
