Hi > On 10/25, KOSAKI Motohiro wrote: > > > > Because execve() makes new mm struct and setup stack and > > copy argv. It mean the task have two mm while execve() temporary. > > Unfortunately this nascent mm is not pointed any tasks, then > > OOM-killer can't detect this memory usage. therefore OOM-killer > > may kill incorrect task. > > > > Thus, this patch added signal->in_exec_mm member and track > > nascent mm usage. > > Stupid question. > > Can't we just account these allocations in the old -mm temporary? > > IOW. Please look at the "patch" below. It is of course incomplete > and wrong (to the point inc_mm_counter() is not safe without > SPLIT_RSS_COUNTING), and copy_strings/flush_old_exec are not the > best places to play with mm-counters, just to explain what I mean. > > It is very simple. copy_strings() increments MM_ANONPAGES every > time we add a new page into bprm->vma. This makes this memory > visible to select_bad_process(). > > When exec changes ->mm (or if it fails), we change MM_ANONPAGES > counter back. > > Most probably I missed something, but what do you think? Because, If the pages of argv is swapping out when processing execve, This accouing doesn't work. Of cource, changing swapping-out logic is one of way. But I did hope no VM core logic change. taking implict mlocking argv area during execve is also one of option. But I did think implicit mlocking is more risky. Is this enough explanation? Please don't hesitate say "no". If people don't like my approach, I don't hesitate change my thinking. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>