> There was a recent proposal to do just that, but current patches in -rcu
> use kfree_bulk(). It doesn't look to me that this works for kfvree()
> under the covers in its current form. Could it be upgraded to handle
> this case?
It would take a bit more fiddling, but nothing too difficult.
// from include/linux/mm.h
static inline bool is_vmalloc_addr(const void *x)
{
unsigned long addr = (unsigned long)x;
return addr >= VMALLOC_START && addr < VMALLOC_END;
}
// ... which could also be written as (addr - VMALLOC_START) < VMALLOC_TOTAL
// from mm/util.c
void kvfree(const void *addr)
{
if (is_vmalloc_addr(addr))
vfree(addr);
else
kfree(addr);
}
... so you could easily do the filtering yourself while forming the
kfree_bulk array.
vfree(p) itself is a wrapper around __vunmap(p, 1). After some
error-checking, it checks if it's called in interrupt context,
If not, it does the __vunmap synchronously. If it *is* in interrupt
context, the freed object is put on a linked list and a work queue
does the __vunmap later.
