Changes from the original implementation:
- Fragmentation is handled by the function m_fragment, which can
be called from whereever fragmentation is needed. Note that this
function is wrapped in #ifdef MBUF_STRESS_TEST to discourage non-testing
use.
- m_fragment works slightly differently from the old fragmentation
code in that it allocates a seperate mbuf cluster for each fragment.
This defeats dma_map_load_mbuf/buffer's feature of coalescing adjacent
fragments. While that is a nice feature in practice, it nerfed the
usefulness of mbuf_stress_test.
- Add two modes of random fragmentation. Chains with fragments all of
the same random length and chains with fragments that are each uniquely
random in length may now be requested.
o add locking
o strip irrelevant spl's
o split malloc types to better account for memory use
o remove unused IPSEC_NONBLOCK_ACQUIRE code
o remove dead code
Sponsored by: FreeBSD Foundation
NB: There is a known LOR on the forwarding path; this needs to be resolved
together with a similar issue in the bridge. For the moment it is
believed to be benign.
Sponsored by: FreeBSD Fondation
o remove irrlevant spl
Notes:
1. We don't lock domain list traversals as this is safe until we start
removing domains.
2. The calculation of max_datalen in net_init_domain appears safe as
noone depends on max_hdr and max_datalen having consistent values.
3. Giant is still held for fast and slow timeouts; this must stay until
each timeout routine is properly locked (coming soon).
Sponsored by: FreeBSD Fondation
with the vendor sendmail distribution. By doing so, we avoid mergemaster
warnings after every 'make' in /etc/mail/.
Reported by: Jeremy Chadwick <koitsu@parodius.com>
MFC after: 3 days
X-MFC after: and re approval
to announce the demise of varargs support in GCC versions 3.3+ and to
direct users to stdarg.h instead.
Fall back to machine/varargs.h for older GCC versions.
bail out if the buffer is not already present.
- The buffer returned by incore() is not locked and should not be sent to
brelse(). Use getblk() with the new GB_NOCREAT flag to preserve the
desired semantics.
caller to acquire it. This permits drain_output() to be done atomically
with other operations as well as reducing the number of lock operations.
- Assert that the proper locks are held in drain_output().
- Change getdirtybuf() to accept a mutex as an argument. This mutex is used
to protect the vnode's buf list and the BKGRDWAIT flag. This lock is
dropped when we successfully acquire a buffer and held on return
otherwise. These semantics reduce the number of cumbersome cases in
calling code.
- Pass the mtx from getdirtybuf() into interlocked_sleep() and allow this
mutex to be used as the interlock argument to BUF_LOCK() in the LOCKBUF
case of interlocked_sleep().
- Change the return value of getdirtybuf() to be the resulting locked buffer
or NULL otherwise. This is for callers who pass in a list head that
requires a lock. It is necessary since the lock that protects the list
head must be dropped in getdirtybuf() so that we don't have a lock order
reversal with the buf queues lock in bremfree().
- Adjust all callers of getdirtybuf() to match the new semantics.
- Add a comment in indir_trunc() that points at unlocked access to a buf.
This may also be one of the last instances of incore() in the tree.
growable (stack) entries that not only grow down, but also grow up.
Have vm_map_growstack() take these flags into account when growing
an entry.
This is the first step in adding support for upward growable stacks.
It is a required feature on ia64 to support the register stack (or
rstack as I like to call it -- it also means reverse stack). We do
not currently create rstacks, so the upward growing is not exercised
and the change should be a functional no-op.
Reviewed by: alc
