Rewrite lockrange and unlockrange. The lock table is now a fixed
size, so there is no possibility for race conditions when expanding.
The current size (256 locked ranges) should be large enough that it
makes no sense to expand it. To do expansion right would require
quiescing the plex (requiring at least 256 I/O completions), and the
performance implications are horrendous.
Add a mutex per plex for accessing the lock table.
Based on analysis by: tegge
This should eliminate one case of foot shooting .
vinum_scandisk: If a drive in the partition table is downed, free it.
This duplicates code for the compatibility partition, which for some
reason was omitted here.
m_reclaim() and re-acquire it when m_reclaim() returns. This means that
we now call the drain routines without holding the mutex lock and
recursing into it. This was done for mainly two reasons:
(i) Avoid the long recursion; long recursions are typically bad and this
is the case here because we block all other code from freeing mbufs
if they need to. Doing that is kind of counter-productive, since we're
really hoping that someone will free.
(ii) More importantly, avoid a potential lock order reversal. Right now,
not all the locks have been added to our networking code; but
without this change, we're introducing the possibility for deadlock.
Consider for example ip_drain(). We will likely eventually introduce
a lock for ipq there, and so ip_freef() will be called with ipq lock
held. But, ip_freef() calls m_freem() which in turn acquires the
mmbfree lock. Since we were previously calling ip_drain() with mmbfree
held, our lock order would be: mmbfree->ipq->mmbfree. Some other code
may very well lock ipq first and then call ip_freef(). This would
result in the regular lock order, ipq->mmbfree. Clearly, we have
deadlock if one thread acquires the ipq lock and sits waiting for
mmbfree while another thread calling m_reclaim() acquires mmbfree
and sits waiting for the ipq lock.
Also, make sure to add a comment above m_reclaim()'s definition briefly
explaining this. Also document this above the call to m_reclaim() in
m_mballoc_wait().
Suggested and reviewed by: alfred
one memory map. The memory window for the PCIC is identifed by the resource id
for NEWSBUS drivers. pccardd always uses window 0 and rid 0 when setting maps
up. This fix does not affect pccardd's handling of common memory for ed cards.
Reviewed by: imp
be 64 bits wide. The largest known current actual physical implementation
is 40 bits, so BUS_SPACE_MAXADDR should reflect this. It also seems to
me that BUS_SPACE_UNRESTRICTED should b ~0UL, not ~0.
avma1pp_attach_avma1pp, since the former may be called multiple
times and we only want to initialize the mutex once.
Submitted by: Thomas Moestl <tmoestl@gmx.net>
- errno is already set to ENOMEM (as appropriate) when asprintf(),
strdup(), or acl_init() fails
o acl_to_text.c:
- the return value of the initial strdup() is not checked
- errno is already set to ENOMEM (as appropriate) when asprintf
and acl_init() fails
- let the the default: case use 'goto error_label' for consistency
Submitted by: jedgar
