Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).
However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.
This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.
Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Change totalram_pages when a single page is added/removed to the
ballooned list. This avoid totalram_pages to be set erroneously to
max_pfn at boot.
Signed-off-by: Gianluca Guida <gianluca.guida@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Move xen_domain and related tests out of asm-x86 to xen/xen.h so they
can be included whenever they are necessary.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
trivial: fix typo in aic7xxx comment
trivial: fix comment typo in drivers/ata/pata_hpt37x.c
trivial: typo in kernel-parameters.txt
trivial: fix typo in tracing documentation
trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
trivial: remove unnecessary semicolons
trivial: Fix duplicated word "options" in comment
trivial: kbuild: remove extraneous blank line after declaration of usage()
trivial: improve help text for mm debug config options
trivial: doc: hpfall: accept disk device to unload as argument
trivial: doc: hpfall: reduce risk that hpfall can do harm
trivial: SubmittingPatches: Fix reference to renumbered step
trivial: fix typos "man[ae]g?ment" -> "management"
trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
trivial: fix missing printk space in amd_k7_smp_check
trivial: fix typo s/ketymap/keymap/ in comment
trivial: fix typo "to to" in multiple files
trivial: fix typos in comments s/DGBU/DBGU/
...
Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally includes (perhaps a huge amount
of) non-RAM pages. The amount of what actually is usable as storage
should instead be used as a basis here.
Some of the calculations (i.e. those not intending to use high memory)
should likely even use (totalram_pages - totalhigh_pages).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- drivers/xen/events.c did not compile
- xen_setup_hook caused a modpost section warning
- the use of u64 (instead of unsigned long long) together with a %llu
in drivers/xen/balloon.c caused a compiler warning
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
1: make "target_kb" only accept and produce a memory size in kilobytes.
2: add a second "target" file which produces output in bytes, and will accept
memparse input (scaled bytes)
This fixes the rather irritating problem that writing the same value
read back into target_kb would end up shrinking the domain by a factor
of 1024, with generally bad results.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: "dan.magenheimer@oracle.com" <dan.magenheimer@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 1058a75f07 ("xen: actually release
memory when shrinking domain") causes a crash if the page being released
is a highmem page.
If a page is highmem then there is no need to unmap it.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix this:
> It appears that in the upstream balloon driver,
> the call to HYPERVISOR_update_va_mapping is missing
> from decrease_reservation. I think as a result,
> the balloon driver is eating memory but not
> releasing it to Xen, thus rendering the balloon
> driver essentially useless. (Can be observed via xentop.)
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
hypervisor.h had accumulated a lot of crud, including lots of spurious
#includes. Clean it all up, and go around fixing up everything else
accordingly.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix guest kernel crash with CONFIG_XEN_SCRUB_PAGES=y
Jens noticed that scrub_page() has a buggy unmap of the wrong
thing. (virtual address instead of page)
Linus pointed out that the whole scrub_page() code is an unnecessary
reimplementation of clear_highpage() to begin with.
Just use clear_highpage() rather than reimplementing it poorly.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The balloon driver doesn't have any externally callable functions at
the moment, so remove the (effectively empty) header. We can add it
back if we need to.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There are four operating modes Xen code may find itself running in:
- native
- hvm domain
- pv dom0
- pv domU
Clean up predicates for testing for these states to make them more consistent.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove some unused functions:
balloon_update_driver_allowance
balloon_release_driver_page
only used on the (obsolete, removed) flip path in netfront
alloc_empty_pages_and_pagevec
free_empty_pages_and_pagevec
only used in backend drivers; can be reintroduced when needed
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1. Set the class so it doesn't clash with the normal memory class
2. Fix up the sysfs show functions to match the new prototype
3. Clean up use of memparse
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: "viets@work.de" <viets@work.de>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This allow to dynamically generate attributes and share show/store
functions between attributes. Right now most attributes are generated
by special macros and lots of duplicated code. With the attribute
passed it's instead possible to attach some data to the attribute
and then use that in shared low level functions to do different things.
I need this for the dynamically generated bank attributes in the x86
machine check code, but it'll allow some further cleanups.
I converted all users in tree to the new show/store prototype. It's a single
huge patch to avoid unbisectable sections.
Runtime tested: x86-32, x86-64
Compiled only: ia64, powerpc
Not compile tested/only grep converted: sh, arm, avr32
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make the needlessly global balloon_set_new_target() static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fix compilation error of ballon driver on ia64.
extent_start member is pointer argument. On x86 pointer argument for
xen hypercall is passed as virtual address.
On the other hand, ia64 and ppc, pointer argument is passed in pseudo
physical address. (guest physicall address.)
So they must be passed as handle and convert right before issuing hypercall.
CC drivers/xen/balloon.o
linux-2.6-x86/drivers/xen/balloon.c: In function 'increase_reservation':
linux-2.6-x86/drivers/xen/balloon.c:228: error: incompatible types in assignment
linux-2.6-x86/drivers/xen/balloon.c: In function 'decrease_reservation':
linux-2.6-x86/drivers/xen/balloon.c:324: error: incompatible types in assignment
linux-2.6-x86/drivers/xen/balloon.c: In function 'dealloc_pte_fn':
linux-2.6-x86/drivers/xen/balloon.c:486: error: incompatible types in assignment
linux-2.6-x86/drivers/xen/balloon.c: In function 'alloc_empty_pages_and_pagevec':
linux-2.6-x86/drivers/xen/balloon.c:522: error: incompatible types in assignment
make[2]: *** [drivers/xen/balloon.o] Error 1
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The balloon driver allows memory to be dynamically added or removed from the domain,
in order to allow host memory to be balanced between multiple domains.
This patch introduces the Xen balloon driver, though it currently only
allows a domain to be shrunk from its initial size (and re-grown back to
that size). A later patch will add the ability to grow a domain beyond
its initial size.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
