| Age | Commit message (Collapse) | Author |
|---|
|
instead of ordering the source mount list, order the new destination
list which has the advantage that we do not need to wlock the source
namespace, so copying can be done in parallel and we do not need the
copy forward pointer in the Mount structure.
the Mhead back pointer in the Mount strcture was unused, removed.
|
|
there was a race between cunmount() and walk() on Mhead.from as Mhead.from was
unconditionally freed when we cunmount(), but findmount might have already
returned the Mhead in walk(). we have to ensure that Mhead.from is not freed
before the Mhead itself (now done in putmhead() once the reference count of the
Mhead drops to zero).
the Mhead struct contained two unused locks, removing.
no need to hold Pgrp.ns lock in closegrp() as nobody can get to it (refcount
droped to zero).
avoid cclose() and freemount() while holding Mhead.lock or Pgrp.ns locks as
it might block on a hung up fileserver.
remove the debug prints...
cleanup: use nil for pointers, remove redundant nil checks before putmhead().
|
|
Lock
make the Page stucture less than half its original size by getting rid of
the Lock and the lru.
The Lock was required to coordinate the unchaining of pages that where
both cached and on the lru freelist.
now pages have a single next pointer that is used for palloc.head
freelist xor for page cache hash chains in Image.pghash[].
cached pages are not on the freelist anymore, but will be reclaimed
from images by the pager when the freelist runs out of pages.
each Image has its own 512 hash chains for cached page lookup. That is
2MB worth of pages and there should be no collisions for most text images.
page reclaiming can be done without holding palloc.lock as the Image is
the owner of the page hash chains protected by the Image's lock.
reclaiming Image structures can be done quickly by only reclaiming pages from
inactive images, that is images which are not currently in use by segments.
the Ref structure has no Lock anymore. Only a single long that is atomically
incremented or decremnted using cmpswap().
there are various other changes as a consequence code. and lots of pikeshedding,
sorry.
|
|
|
|
make sure not to dereference Proc* nil pointer. this can potentially
happen from devip which has code like:
if(er->read4p)
postnote(er->read4p, 1, "unbind", 0);
the process it is about to kill can zero er->read4p at any time,
so there is the possibility of the condition to be true and then
er->read4p becoming nil.
check if the process has already exited (p->pid == 0) in postnote()
under p->debug qlock.
|
|
postnote does not raise error, so the error label is not
neccesary.
|
|
use resrcwait() when waiting for memory to become available. randomize
the sleep time and properly restore old process status in case tsleep()
gets interrupted.
|
|
|
|
|
