On Thu, Sep 20, 2012 at 04:25:35PM +0900, Atsushi Kumagai wrote: > Hello Vivek, > > On Thu, 13 Sep 2012 10:10:18 -0400 > Vivek Goyal <vgoyal at redhat.com> wrote: > > > Hi Atsushi-san, > > > > How is size of cyclic buffer decided with 1.5.0? In practice I don't think > > asking user for the size is a good idea as user does not know how much > > memory will be left after kernel boot. > > As you said, I don't think asking user for the size is a smart way, either. > So, I agree with your basic idea explained in below. > > > Will it make sense for makedumpfile to automatically determine the buffer > > size based on amount of free memory available in the system. Something > > like use 70-80% of free memory as cyclic buffer. > > Now, I think makedumpfile should automatically choose the lesser of the two below > as the size of cyclic buffer when the size isn't specified: > > a. the size enough for storing the 1st/2nd bitmap for the whole of vmcore > b. the limit size (e.g. 70-80% of free memory) > > However, I don't have a good idea how to determine the appropriate size > for the case of "b". > If someone have a idea for the limit size, please let me know. May be just look at "free" output or "cat /proc/meminfo" and grep for "MemFree" calculate the size of buffer. Thanks Vivek
