paper trail now, this patch is similar to one posted for one of the
preliminary versions of a new armv6 port. I took them and made them
more generic. Option not enabled by default since each board/port has
to provide its own eputc, and possibly do other things as well...
This fires off a kqueue note (of type sendfile) to the configured kqfd
when the sendfile transaction has completed and the relevant memory
backing the transaction is no longer in use by this transaction.
This is analogous to SF_SYNC waiting for the mbufs to complete -
except now you don't have to wait.
Both SF_SYNC and SF_KQUEUE should work together, even if it
doesn't necessarily make any practical sense.
This is designed for use by applications which use backing cache/store
files (eg Varnish) or POSIX shared memory (not sure anything is using
it yet!) to know when a region of memory is free for re-use. Note
it doesn't mark the region as free overall - only free from this
transaction. The application developer still needs to track which
ranges are in the process of being recycled and wait until all
pending transactions are completed.
TODO:
* documentation, as always
Sponsored by: Netflix, Inc.
Callers do that already and additional check races with process
decreasing limits and can result in not growing the table at all, which
is currently not handled.
MFC after: 3 days
Having ncneg diverge with the actual length of the ncneg tailq causes
NULL dereference.
Add assertion that an entry taken from ncneg queue is indeed negative.
Reported by and discussed with: avg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
bio_completed, only manage bio_resid, e.g. sa(4).
Reported and tested by: Manfred Antar <null@pozo.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
They are stored as two separate characters in the vtbuf, so copy-pasting
will cause them to be passed to terminal_input_char() twice. Extend
terminal_input_char() to explicitly discard characters with TF_CJK_RIGHT
set. This causes only the left part to generate input.
o Forward termianl framebuffer ioctl to fbd.
o Forward terminal mmap request to fbd.
o Move inclusion of sys/conf.h to vt.h.
Sponsored by: The FreeBSD Foundation
Introduce a new formatting bit (TF_CJK_RIGHT) that is set when putting a
cell that is the right part of a CJK fullwidth character. This will
allow drivers like vt(9) to support fullwidth characters properly.
emaste@ has a patch to extend vt(9)'s font handling to increase the
number of Unicode -> glyph maps from 2 ({normal,bold)} to 4
({normal,bold} x {left,right}). This will need to use this formatting
bit to determine whether to draw the left or right glyph.
Reviewed by: emaste
covered by sbintime (LONG_MAX seconds).
Some programs use timeout values in excess of 1000 years. The conversion
to sbintime caused wrap-around on overflow, which resulted in short or
negative timeout values. This caused long delays on sockets opened by
affected programs (e.g. OpenSSH).
Kernels compiled without -fno-strict-overflow were not affected, apparently
because the compiler tested the sign of the timeout value before performing
the multiplication that lead to overflow.
When the -fno-strict-overflow option was added to CFLAGS, this optimization
was disabled and the test was performed on the result of the multiplication.
Negative products were caught and resulted in EINVAL being returned, but
wrap-around to positive values just shortened the timeout value to the
residue of the result that could be represented by sbintime.
The fix is to cap the timeout values at the maximum that can be represented
by sbintime, which is 2^31 - 1 seconds or more than 68 years.
After this change, the kernel can be compiled with -fno-strict-overflow
with no ill effects.
MFC after: 3 days
linker_unload_file() rather than kern_kldload() and kern_kldunload(). This
ensures that the handlers are invoked for files that are loaded/unloaded
automatically as dependencies. Previously, they were only invoked for files
loaded by a user.
As a side effect, the kld_load and kld_unload handlers are now invoked with
the kernel linker lock exclusively held.
Reported by: avg
Reviewed by: jhb
MFC after: 2 weeks
to fail and return error.
- Use make_dev_p() in tty_makedevf() instead of make_dev_cred().
- Always pass MAKEDEV_CHECKNAME flag.
- Optionally pass MAKEDEV_REF flag.
- Provide macro for compatibility with old API.
This fixes races with simultaneous creation and desctruction of
ttys, and makes it possible to call tty_makedevf() from device
cloners.
A race in tty_watermarks() still exist, since the latter drops
lock for M_WAITOK allocation. This will be addressed in separate
commit.
Reviewed by: kib
Sponsored by: Nginx, Inc.
child process that were inherited from its parent. However, this should
not be done in the case of a vfork, since the fork handler ends up removing
the tracepoints from the shared vm space, and userland DTrace probes in the
parent will no longer fire as a result.
Now the child of a vfork may trigger userland DTrace probes enabled in its
parent, so modify the fasttrap probe handler to handle this case and handle
the child process in the same way that it would handle the traced process.
In particular, if once traces function foo() in a process that vforks, and
the child calls foo(), fasttrap will treat this call as having come from the
parent. This is the behaviour of the upstream code.
While here, add #ifdef guards to some code that isn't present upstream.
MFC after: 1 month
advisory lock cannot be obtained, prevent double-close of the vnode in
vn_close() called from the fdrop(), by resetting file' f_ops methods.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
This allows it to be better tracked as well as being able to leverage
UMA for more interesting/useful behaviour at a later date.
Sponsored by: Netflix, Inc.
the TTY. In such a case, ttydev_close() is called multiple times and
each time, t_revokecnt is incremented and cv_broadcast() is called for
both the t_outwait and t_inwait condition variables.
Let's say revoke(2) comes in first and gets to call tty_drain() from
ttydev_leave(). Let's say that the revoke comes from init(8) as the
result of running "shutdown -r now". Since shutdown prints various
messages to the console before announing that the machine will reboot
immediately, let's also say that the output queue is not empty and
that tty_drain() has something to do. Let's assume this all happens
on a 9600 baud serial console, so it takes a time to drain.
The shutdown command will exit(2) and as such will end up closing
stdout. Let's say this close will come in second, bump t_revokecnt
and call tty_wakeup(). This has tty_wait() return prematurely and
the next thing that will happen is that the thread doing revoke(2)
will flush the TTY. Since the drain wasn't complete, the flush will
effectively drop whatever is left in t_outq.
This change takes into account that tty_drain() will return ERESTART
due to the fact that t_revokecnt was bumped and in that case simply
call tty_drain() again. The thread in question is already performing
the close so it can safely finish draining the TTY before destroying
the TTY structure.
Now all messages from shutdown will be printed on the serial console.
Obtained from: Juniper Networks, Inc.
In case of 4K allocation quantum that means for allocations up to 128K.
With growth of memory fragmentation these lists may grow to quite a large
sizes (tenths and hundreds of thousands items). Having in one list items
of different sizes in worst case may require full linear list traversal,
that may be very expensive. Having lists for items of single size means
that unless user specify some alignment or border requirements (that are
very rare cases) first item found on the list should satisfy the request.
While running SPEC NFS benchmark on top of ZFS on 24-core machine with
84GB RAM this change reduces CPU time spent in vmem_xalloc() from 8%
and lock congestion spinning around it from 20% to invisible levels.
And that all is by the cost of just 26 more pointers per vmem instance.
If at some point our kernel will start to actively use KVA allocations
with odd sizes above 128K, something may need to be done to bigger lists
also.
the excess code in g_io_check(), bio_resid is also truncated by
g_io_deliver(). As result, bufdonebio() assigns truncated value to
the buffer b_resid field.
Use the residual bio_completed to calculate buffer b_resid from
b_bcount in bufdonebio(), instead of bio_resid, calculated from
bio_length in g_io_deliver().
The issue is seemingly caused by the code rearrange into g_io_check(),
which is not present in stable/10. The change still looks as the
useful change to have in 10 nevertheless.
Reported by: Stefan Hegnauer <stefan.hegnauer@gmx.ch>
Tested by: pho, Stefan Hegnauer <stefan.hegnauer@gmx.ch>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
