possible, and double faults within an SLB trap handler are not. The result
is that it possible to take an SLB fault at any time, on any address, for
any reason, at any point in the kernel.
This lets us do two important things. First, it removes the (soft) 16 GB RAM
ceiling on PPC64 as well as any architectural limitations on KVA space.
Second, it lets the kernel tolerate poorly designed hypervisors that
have a tendency to fail to restore the SLB properly after a hypervisor
context switch.
MFC after: 6 weeks
vm_object_pip_{add,subtract}() on the swap object because the swap
object can't be destroyed while the vnode is exclusively locked.
Moreover, even if the swap object could have been destroyed during
tmpfs_nocacheread() and tmpfs_mappedwrite() this code is broken
because vm_object_pip_subtract() does not wake up the sleeping thread
that is trying to destroy the swap object.
Free invalid pages after an I/O error. There is no virtue in keeping
them around in the swap object creating more work for the page daemon.
(I believe that any non-busy page in the swap object will now always
be valid.)
vm_pager_get_pages() does not return a standard errno, so its return
value should not be returned by tmpfs without translation to an errno
value.
There is no reason for the wakeup on vpg in tmpfs_mappedwrite() to
occur with the swap object locked.
Eliminate printf()s from tmpfs_nocacheread() and tmpfs_mappedwrite().
(The swap pager already spam your console if data corruption is
imminent.)
Reviewed by: kib
MFC after: 3 weeks
M_NOWAIT. Currently, the code allows for sleeping in the ioctl path
to guarantee allocation. However code also handles ENOMEM gracefully, so
propagate this error back to user-space, rather than sleeping while
holding the global pf mutex.
Reviewed by: glebius
Discussed with: bz
The concept of set_rcvar() was nice in theory, but the forks
it creates are a drag on the startup process, which is especially
noticeable on slower systems, such as embedded ones.
vfs_mount_error error message facility provided by the nmount
interface.
Clean up formatting of mount warnings which still need to use
kernel printf's since they do not return errors.
Requested by: Craig Rodrigues <rodrigc@crodrigues.org>
MFC after: 2 weeks
the new NFSv4 server where the code follows the wrong list.
Fortunately, for these fairly rare cases, the lc_stateid[]
lists are normally empty. This patch fixes the code to
follow the correct list.
Reported by: tai.horgan at isilon.com
Discussed with: zack
MFC after: 2 weeks
assignments to the literal values it would have returned.
The concept of set_rcvar() was nice in theory, but the forks
it creates are a drag on the startup process, which is especially
noticeable on slower systems, such as embedded ones.
During the discussion on freebsd-rc@ a preference was expressed for
using ${name}_enable instead of the literal values. However the
code portability concept doesn't really apply since there are so
many other places where the literal name has to be searched for
and replaced. Also, using the literal value is also a tiny bit
faster than dereferencing the variables, and every little bit helps.
On amd64, link_elf_obj.c must specify KERNBASE rather than
VM_MIN_KERNEL_ADDRESS to vm_map_find() because kernel loadable
modules must be mapped for execution in the same upper region
of the kernel map as the kernel code and data segments.
For MIPS32 KERNBASE lies below KVA area (it's less than
VM_MIN_KERNEL_ADDRESS) so basically vm_map_find got whole
KVA to look through. On MIPS64 it's not the case because
KERNBASE is set to the very end of XKSEG, well out of KVA
bounds, so vm_map_find always fails. We should use
VM_MIN_KERNEL_ADDRESS as a base for vm_map_find.
Details obtained from: alc@
The errno message display added in r222292 did not take attempting to
cd to a non-directory or something that cannot be stat()ed into account.
PR: bin/164070
MFC after: 10 days
as the system dump device. This was already allowed for GPT. The Linux
swap metadata at the beginning of the partition should not be disturbed
because the crash dump is written at the end.
Reviewed by: alfred, pjd, marcel
MFC after: 2 weeks
The wtmpcvt(1) utility converts wtmp files to the new format used by
utmpx(3). Now that HEAD has been branched to stable/9 and 9.0 is
released, there is no need for it in HEAD.
MFC after: never
reduce the size of the partition in the example from 128 blocks to 94
blocks so it will end on a 128-block boundary. Also remove the -b
option from the next example.
MFC after: 3 weeks
Depending on device capabilities use different methods to implement it.
Currently used method can be read/set via kern.cam.da.X.delete_method
sysctls. Possible values are:
NONE - no provisioning support reported by the device;
DISABLE - provisioning support was disabled because of errors;
ZERO - use WRITE SAME (10) command to write zeroes;
WS10 - use WRITE SAME (10) command with UNMAP bit set;
WS16 - use WRITE SAME (16) command with UNMAP bit set;
UNMAP - use UNMAP command (equivalent of the ATA DSM TRIM command).
The last two methods (UNMAP and WS16) are defined by SBC specification and
the UNMAP method is the most advanced one. The rest of methods I've found
supported in Linux, and as soon as they were trivial to implement, then
why not? Hope they will be useful in some cases.
Unluckily I have no devices properly reporting parameters of the logical
block provisioning support via respective VPD pages (0xB0 and 0xB2). So
all info I have/use now is the flag telling whether logical block
provisioning is supported or not. As result, specific methods chosen now
by trying different ones in order (UNMAP, WS16, DISABLE) and checking
completion status to fallback if needed. I don't expect problems from this,
as if something go wrong, it should just disable itself. It may disable
even too aggressively if only some command parameter misfit.
Unlike Linux, which executes each delete with separate request, I've
implemented here the same request aggregation as implemented in ada driver.
Tests on SSDs I have show much better results doing it this way: above
8GB/s of the linear delete on Intel SATA SSD on LSI SAS HBA (mps).
Reviewed by: silence on scsi@
MFC after: 2 month
Sponsored by: iXsystems, Inc.
1. as reported by Alexander Fiveg, the allocator was reporting
half of the allocated memory. Fix this by exiting from the
loop earlier (not too critical because this code is going
away soon).
2. following a discussion on freebsd-current
http://lists.freebsd.org/pipermail/freebsd-current/2012-January/031144.html
turns out that (re)loading the dmamap was expensive and not optimized.
This operation is in the critical path when doing zero-copy forwarding
between interfaces.
At least on netmap and i386/amd64, the bus_dmamap_load can be
completely bypassed if the map is NULL, so we do it.
The latter change gives an almost 3x improvement in forwarding
performance, from the previous 9.5Mpps at 2.9GHz to the current
line rate (14.2Mpps) at 1.733GHz. (this is for 64+4 byte packets,
in other configurations the PCIe bus is a bottleneck).
for pidfh in libutil.h in its place.
This allows us to hide the contents of the pidfh structure, and also
allowed removal of the "#ifdef _SYS_PARAM_H" guard from around the
pidfile_* function prototypes.
Suggested by pjd.
