In order to avoid livelock, swapoff() skips over objects with a
nonzero pip count and makes another pass if necessary. Since it is
impossible to know which objects we care about, it would choose an
arbitrary object with a nonzero pip count and wait for it before
making another pass, the theory being that this object would finish
paging about as quickly as the ones we care about. Unfortunately,
we may have slept since we acquired a reference to this object.
Hack around this problem by tsleep()ing on the pointer anyway, but
timeout after a fixed interval. More elegant solutions are possible,
but the ones I considered unnecessarily complicate this rare case.
Also, kill some nits that seem to have crept into the swapoff() code
in the last 75 revisions or so:
- Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since
the latter can be derived from the former.
- Replace swp_pager_find_dev() with something simpler. There's no
need to iterate over the entire list of swap devices just to determine
if a given block is assigned to the one we're interested in.
- Expand the scope of the swhash_mtx in a couple of places so that it
isn't released and reacquired once for every hash bucket.
- Don't drop the swhash_mtx while holding a reference to an object.
We need to lock the object first. Unfortunately, doing so would
violate the established lock order, so use VM_OBJECT_TRYLOCK() and
try again on a subsequent pass if the object is already locked.
- Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
syslog(3) if we are a priveleged program (sshd, su, etc.).
- Make syslogd open an additional socket /var/run/logpriv, with 0600
permissions.
- In libc, try to use this socket.
- Do not loop forever if we are using this socket (partial backout of 1.31)
Reviewed by: dwmalone, Andrea Campi <andrea webcom it>
Approved by: julian (mentor)
MFC after: 1 month
remove limit for 20 sockets.
- Add possibility to specify file mode for sockets created with '-l'.
- Check that socket name in '-l' is absolute.
Reviewed by: dwmalone, Andrea Campi <andrea webcom it>
Approved by: julian (mentor)
out c->c_func, we can't take it after callout_stop(). To take it before
we need to acquire callout_lock, to avoid race. This commit narrows
down area where lock is held, but hack is still present.
This should be redesigned.
Approved by: julian (mentor)
because the necessary files were not imported with the original import.
If somebody really needs it, there is still the devel/pmake port.
This is just the first step and removes just everything that is ifdef'ed out.
Otherwise the code is unchanged.
Checked by: md5
Approved by: no objections on arch@
specifiers.
This helps the port team to decide whether to use local patch for
applications that makes use of these GNU extensions (and hopefully we
can get rid of these patches finally)
Requested by: marcus
_(use space as padding), and 0(zero padding).
These GNU extensions are widely used ones that is worthy for us to
have.
Discussed with: stefanf, roam, -current
Approved by: murray
Prodded by: ports/72722, ports/72723
MFC After: 1 month
