According to Ariane van der Steldt (ari...@stack.nl): > On Thu, Dec 09, 2010 at 10:32:57PM +0100, Wouter Coene wrote: > > + addr = uvm_km_kmemalloc(kernel_map, NULL, PAGE_SIZE, > > + UVM_KMF_CANFAIL | UVM_KMF_ZERO); > > If you specify NULL as your object, you'll be given intr-safe memory. > You want to use kernel object instead:
Ah, now it makes sense. How about this diff: Index: uvm.9 =================================================================== RCS file: /cvs/openbsd/src/share/man/man9/uvm.9,v retrieving revision 1.42 diff -u -a -r1.42 uvm.9 --- uvm.9 9 Nov 2010 16:03:38 -0000 1.42 +++ uvm.9 10 Dec 2010 13:00:05 -0000 @@ -534,7 +534,12 @@ .Fa size bytes of wired memory in the kernel map, zeroing the memory if the .Fa zeroit -argument is non-zero. +argument is non-zero. Unless called on an interrupt-safe map, if memory is +currently unavailable, +.Fn uvm_km_alloc1 +may sleep to wait for resources to be released by other processes. If not +enough memory is available, this function returns +.Dv NULL . .Pp The .Fn uvm_km_kmemalloc @@ -542,6 +547,10 @@ .Fa size bytes of wired kernel memory into .Fa obj . +.Fa obj +can only be +.Dv NULL +when allocating from an interrupt-safe map. The flags can be any of: .Bd -literal #define UVM_KMF_NOWAIT 0x1 /* matches M_NOWAIT */ @@ -608,9 +617,9 @@ bytes of memory in the kernel map, starting at address .Fa addr . .Fn uvm_km_free_wakeup -calls -.Fn thread_wakeup -on the map before unlocking the map. +wakes up any processes waiting for memory on the map (via +.Fn thread_wakeup ) +before unlocking the map. .Sh ALLOCATION OF PHYSICAL MEMORY .nr nS 1 .Ft struct vm_page * Also, maybe a stupid question, but why doesn't the irq-safety of the allocation depend on the VM_MAP_INTRSAFE flag, like for uvm_km_free()? Thanks, Wouter Coene
