[Updated with Nick's current address; previous one bounced] On Mon, 4 Oct 2010 15:22:59 -0500 Scott Wood <scottw...@freescale.com> wrote:
> I'm seeing the in_atomic() check in page_cache_get_speculative() > (linux/pagemap.h:138) fail when running e500 KVM with . Sorry, that should finish as "with CONFIG_DEBUG_VM." > It's coming > from get_user_pages_fast(), from KVM's hva_to_pfn(). This is on kvm.git > plus a few local patches that should be completely unrelated, but it > looks like this code hasn't changed much in a couple years. > > Interrupts are disabled by get_user_pages_fast(), but apparently > preemption was not separately disabled. The comment in > page_cache_get_speculative() says that preemption disabling is done by > rcu_read_lock(), and that "this function must be called inside the same > rcu_read_lock() section as has been used to lookup the page in the > pagecache radix-tree (or page table)". > > Where is this RCU lock supposed to be acquired? I don't see any RCU in > arch/powerpc/mm/gup.c. Is it buried in some macro or function call? > > -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
