hi again :) 2011/10/14 Ezequiel García <elezegarcia@xxxxxxxxxxxx>: > Reading sources I think kernel let the process create several > threads because as there is no real memory usage, the amount of free pages > on each thread allocation is the same. I agree, as long as Copy on Write hasn't kicked in.... sometimes it's the commited amount of memory that matters, sometimes how much memory you really allocate that matters. Around 2006, I wrote an article about Out of Memory killer, somehow related to this issue. Maybe you are interested to read it: http://linuxdevcenter.com/pub/a/linux/2006/11/30/linux-out-of-memory.html > I mean, when I start first thread I have enough free pages to allow > the mmap(). When I start the second, third, etc. I always have the > same amount of free pages, since threads don't alloc any pages they > just 'prepare' the adresses. So, the stack area is shared among those threads? > I'll try to put some printk inside vm_enough_memory() and try to re-run > my tests. Do you think there is any other debugging aproach? IMO, that one way to go :) of course nowadays you have ftrace etc, but still, printk followed by kernel recompilation is still easiest IMHO :) > By the way, I have already solved my problem (weeks ago) by reducing default > thread stack size :) But I would love to understand what happened. Welcome to the OOM world :) > It's a strange scenario for a linux kernel, since I have very low memory > left and zero swap. I think it's not that strange, we just have to understand the behaviour. And perhaps your application must anticipate it by gradually decreasing such memory allocation whenever you hit such error. > Thanks a lot for the help! You welcome and sorry I don't lend too much help here... -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
