pointer types, and remove a huge number of casts from code using it.
Change struct xfile xf_data to xun_data (ABI is still compatible).
If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary. There are no operational changes in this
commit.
requests when the number of free pages is below the reserved threshold.
Previously, VM_ALLOC_ZERO was only honored when the number of free pages
was above the reserved threshold. Honoring it in all cases generally
makes sense, does no harm, and simplifies the code.
to sort out disk-io from file-io in the vm/buffer/filesystem space.
The intent is to sort VOP_STRATEGY calls into those which operate
on "real" vnodes and those which operate on VCHR vnodes. For
the latter kind, the call will be changed to VOP_SPECSTRATEGY,
possibly conditionally for those places where dual-use happens.
Add a default VOP_SPECSTRATEGY method which will call the normal
VOP_STRATEGY. First time it is called it will print debugging
information. This will only happen if a normal vnode is passed
to VOP_SPECSTRATEGY by mistake.
Add a real VOP_SPECSTRATEGY in specfs, which does what VOP_STRATEGY
does on a VCHR vnode today.
Add a new VOP_STRATEGY method in specfs to catch instances where
the conversion to VOP_SPECSTRATEGY has not yet happened. Handle
the request just like we always did, but first time called print
debugging information.
Apart up to two instances of console messages per boot, this amounts
to a glorified no-op commit.
If you get any of the messages on your console I would very much
like a copy of them mailed to phk@freebsd.org
is now synchronized by a mutex, whereas access to user maps is still
synchronized by a lockmgr()-based lock. Why? No single type of lock,
including sx locks, meets the requirements of both types of vm map.
Sometimes we sleep while holding the lock on a user map. Thus, a
a mutex isn't appropriate. On the other hand, both lockmgr()-based
and sx locks release Giant when a thread/process blocks during
contention for a lock. This could lead to a race condition in a legacy
driver (that relies on Giant for synchronization) if it attempts to
kmem_malloc() and fails to immediately obtain the lock. Fortunately,
we never sleep while holding a system map lock.
- Add a mtx_destroy() to vm_object_collapse(). (This allows a bzero()
to migrate from _vm_object_allocate() to vm_object_zinit(), where it
will be performed less often.)
comes along and flushes a file which has been mmap()'d SHARED/RW, with
dirty pages, it was flushing the underlying VM object asynchronously,
resulting in thousands of 8K writes. With this change the VM Object flushing
code will cluster dirty pages in 64K blocks.
Note that until the low memory deadlock issue is reviewed, it is not safe
to allow the pageout daemon to use this feature. Forced pageouts still
use fs block size'd ops for the moment.
MFC after: 3 days
skipping read-only pages, which can result in valuable non-text-related
data not getting dumped, the ELF loader and the dynamic loader now mark
read-only text pages NOCORE and the coredump code only checks (primarily) for
complete inaccessibility of the page or NOCORE being set.
Certain applications which map large amounts of read-only data will
produce much larger cores. A new sysctl has been added,
debug.elf_legacy_coredump, which will revert to the old behavior.
This commit represents collaborative work by all parties involved.
The PR contains a program demonstrating the problem.
PR: kern/45994
Submitted by: "Peter Edwards" <pmedwards@eircom.net>, Archie Cobbs <archie@dellroad.org>
Reviewed by: jdp, dillon
MFC after: 7 days
