On Thu, 18 Oct 2012, Glauber Costa wrote: > > Do we actually need to test PF_KTHREAD when current->mm == NULL? > > Perhaps because of aio threads whcih temporarily adopt a userspace mm? > > I believe so. I remember I discussed this in the past with David > Rientjes and he advised me to test for both. > PF_KTHREAD can do use_mm() to assume an ->mm but hopefully they aren't allocating slab while doing so. Have you considered actually charging current->mm->owner for that memory, though, since the kthread will have freed the memory before unuse_mm() or otherwise have charged it on behalf of a user process, i.e. only exempting PF_KTHREAD? -- 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>