nice of 0. Doing so can cause an infinite loop because they should be
running, but a nice -20 process could prevent them from doing so.
- Add a new flag KEF_PRIOELEV to flag a thread that has had its priority
elevated due to priority propagation. If a thread has had its priority
elevated, we assume that it must go on the current queue and it must
get a slice.
- In sched_userret() if our priority was elevated and we shouldn't have
a timeslice, yield here until we should.
Found/Tested by: glebius
which holds on to just the data structure and the mutex. (The
existing refcount (fd_refcnt) holds onto the open files in the
descriptor.)
The fd_holdcnt is protected by fdesc_mtx, fd_refcnt by FILEDESC_LOCK.
Add fdhold(struct proc *) which gets a hold on the filedescriptors of
the specified proc..
Add fddrop(struct filedesc *) which drops the fd_holdcnt and if zero
destroys the mutex and frees the memory.
Initialize the fd_holdcnt to one in fdinit(). Normal operations on
the filedesc structure will not change it.
In fdfree() use fddrop() to dispose of the mutex and structure. Hold
the FILEDESC_LOCK() until we have cleaned out the contents and carefully
set the fields to null values during cleanup.
Use fdhold()/fddrop() in mountcheckdirs() and sysctl_kern_file().
for ensuring that a process' filedesc is not shared with anybody.
Use it in the two places which previously had private implmentations.
This collects all fd_refcnt handling in kern_descrip.c
nice value above 0, set it to 0 so that it may proceed with haste.
This is especially important on ULE, where adjusting the priority
does not guarantee that a thread will be granted a greater time slice.
specifically, vm_pgmoveco():
1. If vm_pgmoveco() sleeps on a busy page, it must redo the look up
because the page may have been freed.
2. If the receive buffer is copy-on-write due to, for example, a fork,
then although the first vm object in the shadow chain may not contain
a page there may still be one from a backing object that is mapped.
Thus, a pmap_remove() is required for the new page rather than the
backing object's page to been seen by the application.
Also, add some comments to vm_pgmoveco() and update some assertions.
Tested by: ken@
completely. For some reason (that I am still curious about) we started to no
longer manage to finish the initialization before the timeouts run the first
time leading to panics when using uninitialized mutex etc.
The root of this problem is that we currently first link a domain to the
domains list and only later initialize the domain's protocols. This should
be reworked in the future, but with the current API it is not possible in
all situations. We settle with this lazy fix for now.
Tested by: gnn, ru, myself
split the conversion of the remaining three filesystems out from the root
mounting changes, so in one go:
cd9660:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
nfs(client):
Convert to nmount (the simple way, mount_nfs(8) is still necessary).
Add omount compat shims.
Drop COMPAT_PRELITE2 mount arg compatibility.
ffs:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
Remove vfs_omount() method, all filesystems are now converted.
Remove MNTK_WANTRDWR, handling RO/RW conversions is a filesystem
task, and they all do it now.
Change rootmounting to use DEVFS trampoline:
vfs_mount.c:
Mount devfs on /. Devfs needs no 'from' so this is clean.
symlink /dev to /. This makes it possible to lookup /dev/foo.
Mount "real" root filesystem on /.
Surgically move the devfs mountpoint from under the real root
filesystem onto /dev in the real root filesystem.
Remove now unnecessary getdiskbyname().
kern_init.c:
Don't do devfs mounting and rootvnode assignment here, it was
already handled by vfs_mount.c.
Remove now unused bdevvp(), addaliasu() and addalias(). Put the
few necessary lines in devfs where they belong. This eliminates the
second-last source of bogo vnodes, leaving only the lemming-syncer.
Remove rootdev variable, it doesn't give meaning in a global context and
was not trustworth anyway. Correct information is provided by
statfs(/).
vfs_flagopt() for binary/boolean options.
vfs_getopts() for string options
vfs_filteropt() to check for unknown options.
vfs_scanopt() for scanf() like processing of options.
Also add function for setting the stat.f_mntfromname field.
Root filessytems (like NFS) don't have an associated disk device,
and even if they had, the exact semantics would be filesystem
dependent and should be implemented there.
zero-copy receive of jumbo frames. This eliminates the need for the
jumbo frame allocator implemented in kern/uipc_jumbo.c and sys/jumbo.h.
Remove it.
Note: Zero-copy receive of jumbo frames did not work without these changes;
I believe there was insufficient locking on the jumbo vm object.
Tested by: ken@
Discussed with: gallatin@
doesn't. Most of the implementations have grown weeds for this so they
copy some fields from mnt_stat if the passed argument isn't that.
Fix this the cleaner way: Always call the implementation on mnt_stat
and copy that in toto to the VFS_STATFS argument if different.
and that I've verified things seem to basically work. I was able to
boot and hot plug usb devices. Please let me know if this causes
problems for anybody.
The push down of giant has proceeded to the point that this will start
to matter more and more.
and if so call it.
The cmount method will gather and interpret omount() style arguments,
and issue a kern_[v]mount() call to execute the corresponding nmount
operation.
initializations but we did have lofty goals and big ideals.
Adjust to more contemporary circumstances and gain type checking.
Replace the entire vop_t frobbing thing with properly typed
structures. The only casualty is that we can not add a new
VOP_ method with a loadable module. History has not given
us reason to belive this would ever be feasible in the the
first place.
Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.
Give coda correct prototypes and function definitions for
all vop_()s.
Generate a bit more data from the vnode_if.src file: a
struct vop_vector and protype typedefs for all vop methods.
Add a new vop_bypass() and make vop_default be a pointer
to another struct vop_vector.
Remove a lot of vfs_init since vop_vector is ready to use
from the compiler.
Cast various vop_mumble() to void * with uppercase name,
for instance VOP_PANIC, VOP_NULL etc.
Implement VCALL() by making vdesc_offset the offsetof() the
relevant function pointer in vop_vector. This is disgusting
but since the code is generated by a script comparatively
safe. The alternative for nullfs etc. would be much worse.
Fix up all vnode method vectors to remove casts so they
become typesafe. (The bulk of this is generated by scripts)
should not return ERESTART after it caught a signal, otherwise
thr_wake() call will be lost, also a timeout wait should not be
restarted. Final, using wakeup not wakeup_one to be safeness.
