id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	field_blocks	field_dependson	field_seealso
445	slab_reclaim() holds a spinlock when making calls to frame allocator	Jakub Jermář	Jakub Jermář	"`slab_reclaim()` holds a spinlock when making calls to frame allocator. It is actually possible that multiple spinlocks are held along the call path from `slab_reclaim()` to `frame_free()`.

This fact prevents the frame allocator from using normal MUTEX_PASSIVE variant of mutexes in favor of the weird MUTEX_ACTIVE variant of mutexes when waiting for physical memory.

The solution is either to drop all mutexes before delving into the frame allocator from `slab_reclaim()` and carefully reacquiring them after the return, or to modify functions called from `slab_reclaim()` to free memory to a local list which will be processed later on in `slab_reclaim()` after all spinlocks are released. The later is complicated by the fact that slab caches may have user-defined destructors, in which the user can call slab/frame_free() directly.

"	enhancement	new	major		helenos/kernel/generic	mainline