On Thu, Nov 8, 2012 at 1:51 PM, Michal Hocko <mhocko@xxxxxxx> wrote: > On Thu 08-11-12 01:27:00, David Rientjes wrote: >> test_set_oom_score_adj() and compare_swap_oom_score_adj() are used to >> specify that current should be killed first if an oom condition occurs in >> between the two calls. >> >> The usage is >> >> short oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX); >> ... >> compare_swap_oom_score_adj(OOM_SCORE_ADJ_MAX, oom_score_adj); >> >> to store the thread's oom_score_adj, temporarily change it to the maximum >> score possible, and then restore the old value if it is still the same. >> >> This happens to still be racy, however, if the user writes >> OOM_SCORE_ADJ_MAX to /proc/pid/oom_score_adj in between the two calls. >> The compare_swap_oom_score_adj() will then incorrectly reset the old >> value prior to the write of OOM_SCORE_ADJ_MAX. >> >> To fix this, introduce a new oom_flags_t member in struct signal_struct >> that will be used for per-thread oom killer flags. KSM and swapoff can >> now use a bit in this member to specify that threads should be killed >> first in oom conditions without playing around with oom_score_adj. >> >> This also allows the correct oom_score_adj to always be shown when >> reading /proc/pid/oom_score. >> >> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> > > I didn't like the previous playing with the oom_score_adj and what you > propose looks much nicer. > Maybe s/oom_task_origin/task_oom_origin/ would be a better fit May be s/oom_task_origin/is_task_origin_oom? Just my 2 cents. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>