On 07/18/2010 01:23 PM, Pekka Enberg wrote: > Nitin Gupta wrote: >> @@ -528,17 +581,32 @@ static int zcache_store_page(struct zcache_inode_rb *znode, >> goto out; >> } >> >> - dest_data = kmap_atomic(zpage, KM_USER0); >> + local_irq_save(flags); > > Does xv_malloc() required interrupts to be disabled? If so, why doesn't the function do it by itself? > xvmalloc itself doesn't require disabling interrupts but zcache needs that since otherwise, we can have deadlock between xvmalloc pool lock and mapping->tree_lock which zcache_put_page() is called. OTOH, zram does not require this disabling of interrupts. So, interrupts are disable separately for zcache case. Thanks, Nitin -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>