Module Name: src
Committed By: thorpej
Date: Sun Aug 16 20:04:36 UTC 2020
Modified Files:
src/sys/arch/alpha/alpha: pmap.c
Log Message:
- Undo part of rev 1.264; go back to not acquiring the pmap lock in
pmap_activate(). As of rev 1.211, the pmap::pm_lev1map field is
stable across the life of the pmap, and so the conditino that
the change in 1.264 was intended to avoid would not have happened
anyway.
- Explicitly use __cacheline_aligned / COHERENCY_UNIT rather than 64
in a couple of places.
- Update comments around the lev1map lifecycle, and add some assertions
to enforce the assumptions being described.
- Remove some dubious DEBUG tests that are not MP-safe.
- Chage some long-form #ifdef DIAGNOSTIC checks / panics to KASSERTs.
- Remove the PMAP_ACTIVATE() macro because it's no longer used anywhere
except for pmap_activate(). Just open-code the equivalent there.
- In pmap_activate(), only perform the SWPCTX if either the PTBR or the
ASN are different than what the PCB already has. Also assert that
preemption is disabled and that the specified lwp is curlwp.
- In pmap_deactivate(), add similar assertions, and add a comment explaining
why a SWPCTX to get off of the deactivated lev1map is not necessaray.
- Refactor some duplicated code in pmap_growkernel() into a new
pmap_kptpage_alloc() function.
- In pmap_growkernel(), assert that any user pmap published on the all-pmaps
list does not reference the kernel_lev1map.
- In pmap_asn_alloc(), get out early if we're called with the kernel pmap,
since all kernel mappings are ASM. Remove bogus assertions around the
value of pmap::pm_lev1map and the current ASN, and simply assert that
pmap::pm_lev1map is never kernel_lev1map. Also assert that preemption
is disabled, since we're manipulating per-cpu data structures.
- Convert the "too much uptime" panic to a simple KASSERT, and update the
comment to reflect that we're only subject to the longer 75 billion year
ASN generation overflow (because CPUs that don't implement ASNs never go
through this code path).
To generate a diff of this commit:
cvs rdiff -u -r1.266 -r1.267 src/sys/arch/alpha/alpha/pmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
