existing code caused problems with some SCSI controllers.
A new sysctl kern.cam.ada.spindown_shutdown has been added that controls
whether or not to spin-down disks when shutting down.
Spinning down the disks unloads/parks the heads - this is
much better than removing power when the disk is still
spinning because otherwise an Emergency Unload occurs which may cause damage
to the actuator.
PR: kern/140752
Submitted by: olli
Reviewed by: arundel
Discussed with: mav
MFC after: 2 weeks
MOD_UNLOAD. This makes it possible to add custom hooks for other module
events.
Return EOPNOTSUPP when there is no callback available.
Pointed out by: jhb
Reviewed by: jhb
MFC after: 1 month
may be left. This fixes a memory leak that can occur when tracing is
disabled on a process via disabling tracing of a specific file (or if
an I/O error occurs with the tracefile) if the process's next system
call is exit(). The trace disabling code clears p_traceflag, so exit1()
doesn't do any KTRACE-related cleanup leading to the leak. I chose to
make the free'ing of pending records synchronous rather than patching
exit1().
- Move KTRACE-specific logic out of kern_(exec|exit|fork).c and into
kern_ktrace.c instead. Make ktrace_mtx private to kern_ktrace.c as a
result.
MFC after: 1 month
root file system (starting with devfs and a synthesized configuration) can
contain directives for mounting another file system as root. The old root
file system is re-mounted under the new root file system (with /.mount or
/mnt as the mount point) to allow access to the underlying file system.
The configuration allows for creating vnode-backed memory disks that can
subsequently be mounted as root. This allows for an efficient and low-
cost way to distribute and boot FreeBSD software images that reside on
some storage media.
When trying a mount, the kernel will wait for the device in question to
arrive. The timeout is configurable and is part of the configuration.
This allows arbitrarily complex GEOM configurations to be constructed
on the fly.
A side-effect of this change is that all root specifications, whether
compiled into the kernel or typed at the prompt can contain root mount
options.
counter on SMU-based systems, which causes FreeBSD to reject the RTC time
when used in a dual-boot environment. Since we don't use the day-of-week
counter anyway, solve this by just not checking that it matches.
MFC after: 3 weeks
- In thr_exit() and kthread_exit(), only remove thread from
hash if it can directly exit, otherwise let exit1() do it.
- In thread_suspend_check(), fix cleanup code when thread needs
to exit.
This change seems fixed the "Bad link elm " panic found by
Peter Holm.
Stress testing: pho
Move debug.ncnegfactor to vfs.ncnegfactor [1].
Provide some descriptions for the namecache related sysctls [1].
Based on the submission by: Rogier R. Mulhuijzen <drwilco drwilco net> [1]
MFC after: 2 weeks
X-MFC-note: remove debug.ncnegfactor in HEAD after MFC
instead of using SIGISMEMBER to test every interesting signal, just
unmask the signal set and let cursig() return one, get the signal
after it returns, call reschedule_signal() after signals are blocked
again.
In kern_sigprocmask(), don't call reschedule_signal() when it is
unnecessary.
In reschedule_signal(), replace SIGISEMPTY() + SIGISMEMBER() with
sig_ffs(), rename variable 'i' to sig.
This is based on the same approach as used in panic().
In theory parallel execution of generic_stop_cpus() could lead to two CPUs
stopping each other and everyone else, and thus a total system halt.
Also, in theory, we should have some smarter locking here, because two
(or more CPUs) could be stopping unrelated sets of CPUs.
But in practice, it seems, this function is only used to stop
"all other" CPUs.
Additionally, I took this opportunity to make amd64-specific suspend_cpus()
function use generic_stop_cpus() instead of rolling out essentially
duplicate code.
This code is based on code by Sandvine Incorporated.
Suggested by: mdf
Reviewed by: jhb, jkim (earlier version)
MFC after: 2 weeks
breakage for old mount(2) syscall, since most struct <filesystem>_args
embed export_args. The mount(2) is supposed to provide ABI
compatibility for pre-nmount mount(8) binaries, so restore ABI to
pre-r184588.
Requested and reviewed by: bde
MFC after: 2 weeks
This is to prevent caching of its value in a register when it is checked
and modified by multiple CPUs in parallel.
Also, move the variable into the scope of the only function that uses it.
Reviewed by: jhb
Hint from: mdf
MFC after: 1 week
rwlock to protect the table. In old code, thread lookup is done with
process lock held, to find a thread, kernel has to iterate through
process and thread list, this is quite inefficient.
With this change, test shows in extreme case performance is
dramatically improved.
Earlier patch was reviewed by: jhb, julian
A new function prep_devname() sanitizes a device name by removing
leading and redundant sequential slashes. The function returns an error
for names which already exist or are considered invalid.
A new flag MAKEDEV_CHECKNAME for make_dev_p(9) and make_dev_credf(9)
indicates that the caller is prepared to handle an error related to the
device name. An invalid name triggers a panic if the flag is not
specified.
Document the MAKEDEV_CHECKNAME flag in the make_dev(9) manual page.
Idea from: kib
Reviewed by: kib
it (the root mount code) into a new file called vfs_mountroot.c
The split is almost trivial, as the code is almost perfectly
non-intertwined. The only adjustment needed was to move the UMA
zone allocation out of vfs_mountroot() [in vfs_mountroot.c] and
into vfs_mount.c, where it had to be done as a SYSINIT [see
vfs_mount_init()].
There are no functional changes with this commit.
the linker_load_file methods. The change is that the consequent
linker_file_unload() call is not under the vnode lock anymore.
This prevents the LOR between kernel linker sx xlock and vnode lock,
because linker_file_unload() relocks kernel linker lock.
MFC after: 2 weeks
SI_SUB_RUN_SCHEDULER+SI_ORDER_ANY should only be used to call
scheduler() function which turns the initial thread into swapper proper
and thus there is no further SYSINIT processing.
Other SYSINITs with SI_SUB_RUN_SCHEDULER+SI_ORDER_ANY may get ordered
after scheduler() and thus never executed. That particular relative
order is semi-arbitrary.
Thus, change such places to use SI_ORDER_MIDDLE.
Also, use SI_ORDER_MIDDLE instead of correct, but less appealing,
SI_ORDER_ANY - 1.
MFC after: 1 week
This is a followup to r212964.
stack_print call chain obtains linker sx lock and thus potentially may
lead to a deadlock depending on a kind of a panic.
stack_print_ddb doesn't acquire any locks and it doesn't use any
facilities of ddb backend.
Using stack_print_ddb outside of DDB ifdef required taking a number of
helper functions from under it as well.
It is a good idea to rename linker_ddb_* and stack_*_ddb functions to
have 'unlocked' component in their name instead of 'ddb', because those
functions do not use any DDB services, but instead they provide unlocked
access to linker symbol information. The latter was previously needed
only for DDB, hence the 'ddb' name component.
Alternative is to ditch unlocked versions altogether after implementing
proper panic handling:
1. stop other cpus upon a panic
2. make all non-spinlock lock operations (mutex, sx, rwlock) be a no-op
when panicstr != NULL
Suggested by: mdf
Discussed with: attilio
MFC after: 2 weeks
