Commit Graph

7122 Commits

Author SHA1 Message Date
Milton Miller 188d2ce78f [PATCH] ppc64: Remove old includes
Trim some no longer needed includes from udbg.c and friends.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:37 +10:00
Milton Miller c8f1c8be62 [PATCH] ppc64: Take udbg out of ppc_md
Take udbg out of ppc_md. Allows us to not overwrite early udbg inits
when assigning ppc_md.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:36 +10:00
Milton Miller 7f853352e7 [PATCH] ppc64: Split SCC and 15550 udbg code
Split scc and 15550 functions from udbg each into their own file.
This makes them more symetric with the lpar and btext code.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:36 +10:00
Milton Miller 37548d58e5 [PATCH] ppc64: Make udbg_init_uart set the ppc_md udbg methods.
make udbg_init_uart set the ppc_md udbg methods.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:36 +10:00
Milton Miller cb14c4d641 [PATCH] ppc64: Clean up CR handling
Make the 16550 and real mode 16550 use tail recursion like the scc code
instead of repeating the routine except for the character sent.

Gcc recoginizes the tail recursion and handles it efficently without
stack allocations.  The maple real putc shrinks from 188 to 104 bytes
of instructions.  udbg_putc drops from 188 to 140 bytes.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:36 +10:00
Milton Miller 5fdabaab01 [PATCH] ppc64: Remove dummy getc routines
Now that xmon is fixed we should not need the dummy getc routines.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:35 +10:00
Milton Miller 41be31b7d6 [PATCH] ppc64: dont bypass ppc_md.udbg* functions
udbg_getc_poll is a ppc_md function.   don't call directly into udbg.c

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:35 +10:00
Milton Miller cdcd318fef [PATCH] ppc64: Add missing include
inline pmac_call_feature references ppc_md so include asm/machdep.h
in asm/pmac_feature.h

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:35 +10:00
Linus Torvalds 67d2c36e90 Merge watchdog driver updates
Automated merge from

	master.kernel.org:/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog

failed due to duplicate different changes to Kconfig file. Manually fixed
up. Hopefully.
2005-09-05 06:00:45 -07:00
Linus Torvalds 94f8c66e5e Merge branch 'upstream' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev 2005-09-05 05:50:36 -07:00
Jeff Garzik d0bd99299b /spare/repo/libata-dev branch 'iomap-try3' 2005-09-05 05:20:33 -04:00
Jeff Garzik 586a4ac509 /spare/repo/libata-dev branch 'master' 2005-09-05 05:16:50 -04:00
Linus Torvalds da1f136c26 Merge master.kernel.org:/home/rmk/linux-2.6-mmc 2005-09-05 00:18:09 -07:00
Linus Torvalds 64c4813d9e Merge master.kernel.org:/home/rmk/linux-2.6-arm 2005-09-05 00:17:25 -07:00
Linus Torvalds babf68de58 Merge master.kernel.org:/home/rmk/linux-2.6-serial 2005-09-05 00:14:47 -07:00
Linus Torvalds e766f1cc59 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6 2005-09-05 00:12:58 -07:00
Linus Torvalds 48467641bc Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2005-09-05 00:11:50 -07:00
Martin Schwidefsky 3863e72414 [PATCH] s390: disconnected 3270 console
Fix reboot with a disconnected 3270 console.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:29 -07:00
Heiko Carstens 9513e5e3f5 [PATCH] s390: spinlock corner case
On s390 the lock value used for spinlocks consists of the lower 32 bits of the
PSW that holds the lock.  If this address happens to be on a four gigabyte
boundary the lock is left unlocked.  This allows other cpus to grab the same
lock and enter a lock protected code path concurrently.  In theory this can
happen if the vmalloc area for the code of a module crosses a 4 GB boundary.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:29 -07:00
Heiko Carstens c563077e52 [PATCH] s390: compat system calls
Use TIF bit to tell if a process is running in 31 bit mode instead of checking
the addressing mode bits of the PSW.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:29 -07:00
Eric Rossman 2dee702fcb [PATCH] s390: crypto driver update
crypto device driver update:

 - Suppress syslog messages for some return codes.

 - Fix incorrect bounds checking in /proc interface.

 - Remove hotplug calls.

 - Remove linux version checks.

 - Remove device workqueue on module unload.

Signed-off-by: Eric Rossman <edrossma@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:29 -07:00
Martin Schwidefsky b6d09449d5 [PATCH] s390: pfault interrupt race
There is a race in pfault_interrupt.  That function gets called two times for
each pfault notification.  Once with a subcode of 0 to indicate that a real
page is not available and once with a subcode of 0x80 to indicate that the
page is present again.

Since the two external interrupts can be delivered on two different cpus the
order in which the two calls are made is unpredictable.  It is possible that
the subcode 0x80 interrupt is completed before the subcode 0x00 interrupt has
done the wake_up() call.

To avoid calling wake_up() on an already removed task structure proper task
structure reference counting is needed.  Increase the reference counter in the
subcode 0x00 interrupt before setting pfault_wait to zero and return the
reference after the wake_up call.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:28 -07:00
Cornelia Huck 4c24da79e2 [PATCH] s390: reIPL fix and extern/static inline
Common i/o layer changes:

- Collect the irb at the correct subchannel when waiting for the clear
  interrupt during subchannel cleaning befor reIPL - don't stop at the first
  interrupt that comes in.

- Change "extern __inline__" to "static inline".

- Remove unneeded qdio includes.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:28 -07:00
Horst Hummel fd49f41aa0 [PATCH] s390: 64 bit diag250 support
Add support for diag 250 access to dasd devices for 64 bit kernels.  In
addition fix detach/attach for diag disks.  The VM control block needs to get
recreated by a call to mdsk_init_io.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:27 -07:00
Horst Hummel c6eb7b7703 [PATCH] s390: deadlock in dasd_devmap
Reintroduce a read-only copy of the devmap features in the device struct.
This is necessary to solve a deadlock on the dasd_devmap_lock which is
acquired by dasd_get_features called from the dasd tasklet.  The current
implementation of devmap doesn't allow to call any devmap function from
interrupt or softirq context.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:26 -07:00
Michael Holzheu 942eaabd5d [PATCH] s390: debug feature changes
debug feature changes/bug fixes:

- Use get_clock() function instead of private inline assembly.

- Use 'struct timeval' instead of 'struct timespec' for call to
  tod_to_timeval().  Now the microsecond part of the timestamp is correct
  again.

- Fix a locking problem: when creating a snapshot of the current content
  of the debug areas, lock the entire debug_info object.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:26 -07:00
Martin Schwidefsky ae6aa2ea89 [PATCH] s390: machine check handler bugs
The new machine check handler still has a few bugs.

1) The system entry time has to be stored in the machine check handler,

2) the machine check return psw may not be stored at the usual place
   because it might overwrite the return psw of the interrupted context,

3) the return address for the call to s390_handle_mcck in the i/o interrupt
   handler is not correct,

4) the system call cleanup has to take the different save area of the
   machine check handler into account,

5) the machine check handler may not call UPDATE_VTIME before
   CREATE_STACK_FRAME, and

6) the io leave path needs a critical section cleanup to make sure that the
   TIF_MCCK_PENDING bit is really checked before switching back to user space.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:25 -07:00
Adrian Bunk 4c139862b8 [PATCH] xtensa: delete accidental file
This file seems to be an accident.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:25 -07:00
Adrian Bunk d99cf715a0 [PATCH] xtensa: replace 'extern inline' with 'static inline'
"extern inline" doesn't make sense.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:25 -07:00
Jeff Dike 7ef9390541 [PATCH] uml: fix x86_64 page leak
We were leaking pmd pages when 3_LEVEL_PGTABLES was enabled.  This fixes that.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00
Bodo Stroesser f9dfefe423 [PATCH] uml: fix advanced sysemu check
cleanup and fix the check for advanced sysemu (PTRACE_SYSEMU_SINGLESTEP
option)

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00
Bodo Stroesser d9838d8653 [PATCH] uml: allow host capability usage to be disabled
Add new cmdline setups:
  - noprocmm
  - noptracefaultinfo
In case of testing, they can be used to switch off usage of
/proc/mm and PTRACE_FAULTINFO independently.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00
Bodo Stroesser 07bf731e4b [PATCH] uml: skas0 stubs now check system call return values
Change syscall-stub's data to include a "expected retval".

Stub now checks syscalls retval and aborts execution of syscall list, if
retval != expected retval.

run_syscall_stub prints the data of the failed syscall, using the data pointer
and retval written by the stub to the beginning of the stack.

one_syscall_stub is removed, to simplify code, because only some instructions
are saved by one_syscall_stub, no host-syscall.

Using the stub with additional data (modify_ldt via stub)
is prepared also.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00
Bodo Stroesser 8b51304ed3 [PATCH] uml: increase granularity of host capability checking
This change enables SKAS0/SKAS3 to work with all combinations of /proc/mm and
PTRACE_FAULTINFO being available or not.

Also it changes the initialization of proc_mm and ptrace_faultinfo slightly,
to ease forcing SKAS0 on a patched host.  Forcing UML to run without /proc/mm
or PTRACE_FAULTINFO by cmdline parameter can be implemented with a setup
resetting the related variable.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00
Gennady Sharapov 60d339f6fe [PATCH] uml: move libc-dependent startup and signal code
The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from process.c file under os-Linux dir and join
process.c and process_kern.c files.

Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00
Jeff Dike 09ace81c1d [PATCH] uml: add host AIO support to block driver
This adds AIO support to the ubd driver.

The driver breaks a struct request into IO requests to the host, based on the
hardware segments in the request and on any COW blocks covered by the request.

The ubd IO thread is gone, since there is now an equivalent thread in the AIO
module.

There is provision for multiple outstanding requests now.  Requests aren't
retired until all pieces of it have been completed.  The AIO requests have a
shared count, which is decremented as IO operations come in until it reaches
0.  This can be possibly moved to the request struct - haven't looked at this
yet.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:23 -07:00
Jeff Dike 75e5584c89 [PATCH] uml: use host AIO support
This patch makes UML use host AIO support when it (and
/usr/include/linux/aio_abi.h) are present.  This is only the support, with no
consumers - a consumer is coming in the next patch.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:23 -07:00
Al Viro 30f7dabb08 [PATCH] uml: build cleanups
Added missing include list to uml AFLAGS

Killed magic for stubs.  [So] - it was needed only because of messed AFLAGS
Switched segv_stubs.c to kernel CFLAGS sans profile, instead of user ones
Killed STUBS_CFLAGS - it's not needed and the only remaining use had been
gratitious - it only polluted CFLAGS

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:23 -07:00
Jeff Dike e32dacb9f4 [PATCH] uml: system call path cleanup
This merges two sets of files which had no business being split apart in the
first place.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:23 -07:00
Jeff Dike 08964c565b [PATCH] uml: merge duplicated page table code
There is a lot of code which is duplicated between the 2 and 3 level
implementation, with the only difference that the 3-level implementation is a
bit more generalized (instead of accessing directly pte_t.pte, it uses the
appropriate access macros).

So this code is joined together.

As obvious, a "core code nice cleanup" is not a "stability-friendly patch" so
usual care applies.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:22 -07:00
Jeff Dike c56004901f [PATCH] uml: TLB operation batching
This adds VM op batching to skas0.  Rather than having a context switch to and
from the userspace stub for each address space change, we write a number of
operations to the stub data page and invoke a different stub which loops over
them and executes them all in one go.

The operations are stored as [ system call number, arg1, arg2, ... ] tuples.

The set is terminated by a system call number of 0.  Single operations, i.e.
page faults, are handled in the old way, since that is slightly more
efficient.

For a kernel build, a minority (~1/4) of the operations are part of a set.
These sets averaged ~100 in length, so for this quarter, the context switching
overhead is greatly reduced.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:22 -07:00
Jeff Dike 77fa5adcda [PATCH] uml: remove duplicated exports
Al Viro <viro@parcelfarce.linux.theplanet.co.uk> spotted a bunch of duplicated
exports - this removes them.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:22 -07:00
Jeff Dike 02edeb586a [PATCH] uml: mark SMP on UML/x86_64 as broken
Noticed by Al Viro <viro@parcelfarce.linux.theplanet.co.uk> - SMP on x86_64 is
fundamentally broken due to UML's reuse of the host arch's percpu stuff.  This
is OK on x86, but the x86_64 pda stuff just won't work for UML.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:22 -07:00
Al Viro 13abf81301 [PATCH] uml: remove libc reference in build
Remove an unneeded reference to libc.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:22 -07:00
Al Viro 93ea5a5b5c [PATCH] uml: build cleanup
Build cleanups

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:22 -07:00
Jeff Dike ec7cf783dd [PATCH] uml: error path cleanup
This cleans up the error path in ubd_open, causing it now to call ubd_close
appropriately when something fails.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:21 -07:00
Al Viro 7efd08c855 [PATCH] uml: fix a macro typo
Fix a macro typo which could break if the macro is passed arguments with
side-effects.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:21 -07:00
Al Viro e54a5dfb96 [PATCH] uml: fix signal frame copy_user
The copy_user stuff in the signal frame code was broke.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:21 -07:00
Paolo 'Blaisorblade' Giarrusso 3b52166cf7 [PATCH] uml: fault handler micro-cleanups
Avoid chomping low bits of address for functions doing it by themselves,
fix whitespace, add a correctness checking.

I did this for remap-file-pages protection support, it was useful on its
own too.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:21 -07:00
Paolo 'Blaisorblade' Giarrusso 1e40cd383c [PATCH] uml: fixes performance regression in activate_mm and thus exec()
Normally, activate_mm() is called from exec(), and thus it used to be a
no-op because we use a completely new "MM context" on the host (for
instance, a new process), and so we didn't need to flush any "TLB entries"
(which for us are the set of memory mappings for the host process from the
virtual "RAM" file).

Kernel threads, instead, are usually handled in a different way.  So, when
for AIO we call use_mm(), things used to break and so Benjamin implemented
activate_mm().  However, that is only needed for AIO, and could slow down
exec() inside UML, so be smart: detect being called for AIO (via
PF_BORROWED_MM) and do the full flush only in that situation.

Comment also the caller so that people won't go breaking UML without
noticing.  I also rely on the caller's locks for testing current->flags.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:21 -07:00