There is no need to keep the dentry pointer around for the created
debugfs file, as it is only needed when removing it from the system.
When it is to be removed, ask debugfs itself for the pointer, to save on
storage and make things a bit simpler.
Cc: Nadav Amit <namit@vmware.com>
Cc: "VMware, Inc." <pv-drivers@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org
Acked-by: Nadav Amit <namit@vmware.com>
Link: https://lore.kernel.org/r/20210216151209.3954129-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Through a labyrinthian sequence of includes, usage of virt_to_phys() is
dependent on the include of asm/io.h in x86's asm/realmode.h, which is
included in x86's asm/acpi.h and thus by linux/acpi.h. Explicitly
include linux/io.h to break the dependency on realmode.h so that a
future patch can remove the realmode.h include from acpi.h without
breaking the build.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20191126165417.22423-9-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups. Because of this, there is going
to be some merge issues with your tree at the moment, I'll follow up
with the expected resolutions to make it easier for you.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups (will cause build warnings
with s390 and coresight drivers in your tree)
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse
easier due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of merge
issues that Stephen has been patient with me for. Other than the merge
issues, functionality is working properly in linux-next :)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Julien Freche <jfreche@vmware.com>
Cc: "VMware, Inc." <pv-drivers@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org
Acked-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The hypervisor might refuse to inflate pages. While the balloon driver
handles this scenario correctly, a refusal to inflate a 2MB pages might
cause the same page to be allocated again later just for its inflation
to be refused again. This wastes energy and time.
To avoid this situation, split the 2MB page to 4KB pages, and then try
to inflate each one individually. Most of the 4KB pages out of the 2MB
should be inflated successfully, and the balloon is likely to prevent
the scenario of repeated refused inflation.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a shrinker to the VMware balloon to prevent out-of-memory events.
We reuse the deflate logic for this matter. Deadlocks should not happen,
as no memory allocation is performed while the locks of the
communication (batch/page) and page-list are taken. In the unlikely
event in which the configuration semaphore is taken for write we bail
out and fail gracefully (causing processes to be killed).
Once the shrinker is called, inflation is postponed for few seconds.
The timeout is updated without any lock, but this should not cause any
races, as it is written and read atomically.
This feature is disabled by default, since it might cause performance
degradation.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for compaction for VMware balloon. Since unlike the virtio
balloon, we also support huge-pages, which are not going through
compaction, we keep these pages in vmballoon and handle this list
separately. We use the same lock to protect both lists, as this lock is
not supposed to be contended.
Doing so also eliminates the need for the page_size lists. We update the
accounting as needed to reflect inflation, deflation and migration to be
reflected in vmstat.
Since VMware balloon now provides statistics for inflation, deflation
and migration in vmstat, select MEMORY_BALLOON in Kconfig.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big char/misc driver patch pull request for 5.1-rc1.
The largest thing by far is the new habanalabs driver for their AI
accelerator chip. For now it is in the drivers/misc directory but will
probably move to a new directory soon along with other drivers of this
type.
Other than that, just the usual set of individual driver updates and
fixes. There's an "odd" merge in here from the DRM tree that they asked
me to do as the MEI driver is starting to interact with the i915 driver,
and it needed some coordination. All of those patches have been
properly acked by the relevant subsystem maintainers.
All of these have been in linux-next with no reported issues, most for
quite some time.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big char/misc driver patch pull request for 5.1-rc1.
The largest thing by far is the new habanalabs driver for their AI
accelerator chip. For now it is in the drivers/misc directory but will
probably move to a new directory soon along with other drivers of this
type.
Other than that, just the usual set of individual driver updates and
fixes. There's an "odd" merge in here from the DRM tree that they
asked me to do as the MEI driver is starting to interact with the i915
driver, and it needed some coordination. All of those patches have
been properly acked by the relevant subsystem maintainers.
All of these have been in linux-next with no reported issues, most for
quite some time"
* tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (219 commits)
habanalabs: adjust Kconfig to fix build errors
habanalabs: use %px instead of %p in error print
habanalabs: use do_div for 64-bit divisions
intel_th: gth: Fix an off-by-one in output unassigning
habanalabs: fix little-endian<->cpu conversion warnings
habanalabs: use NULL to initialize array of pointers
habanalabs: fix little-endian<->cpu conversion warnings
habanalabs: soft-reset device if context-switch fails
habanalabs: print pointer using %p
habanalabs: fix memory leak with CBs with unaligned size
habanalabs: return correct error code on MMU mapping failure
habanalabs: add comments in uapi/misc/habanalabs.h
habanalabs: extend QMAN0 job timeout
habanalabs: set DMA0 completion to SOB 1007
habanalabs: fix validation of WREG32 to DMA completion
habanalabs: fix mmu cache registers init
habanalabs: disable CPU access on timeouts
habanalabs: add MMU DRAM default page mapping
habanalabs: Dissociate RAZWI info from event types
misc/habanalabs: adjust Kconfig to fix build errors
...
Mark inflated and never onlined pages PG_offline, to tell the world that
the content is stale and should not be dumped.
[david@redhat.com: use vmballoon_page_in_frames more widely]
Link: http://lkml.kernel.org/r/20181122100627.5189-7-david@redhat.com
Link: http://lkml.kernel.org/r/20181119101616.8901-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Nadav Amit <namit@vmware.com>
Cc: Xavier Deguillard <xdeguillard@vmware.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julien Freche <jfreche@vmware.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Hansen <chansen3@cisco.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Pankaj gupta <pagupta@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We added some locking to this function but forgot to drop the lock on
these two error paths. This bug would lead to an immediate deadlock.
Fixes: c7b3690fb1 ("vmw_balloon: stats rework")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the balloon driver would fail to run if memory is greater
than 16TB of vRAM. Previous patches have already converted the balloon
target and size to 64-bit, so all that is left to do add is to avoid
asserting memory is smaller than 16TB if the hypervisor supports 64-bits
target.
The driver advertises a new capability VMW_BALLOON_64_BITS_TARGET.
Hypervisors that support 16TB of memory or more will report that this
capability is enabled.
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big set of char and misc driver patches for 4.21-rc1.
Lots of different types of driver things in here, as this tree seems to
be the "collection of various driver subsystems not big enough to have
their own git tree" lately.
Anyway, some highlights of the changes in here:
- binderfs: is it a rule that all driver subsystems will eventually
grow to have their own filesystem? Binder now has one to handle the
use of it in containerized systems. This was discussed at the
Plumbers conference a few months ago and knocked into mergable shape
very fast by Christian Brauner. Who also has signed up to be
another binder maintainer, showing a distinct lack of good judgement :)
- binder updates and fixes
- mei driver updates
- fpga driver updates and additions
- thunderbolt driver updates
- soundwire driver updates
- extcon driver updates
- nvmem driver updates
- hyper-v driver updates
- coresight driver updates
- pvpanic driver additions and reworking for more device support
- lp driver updates. Yes really, it's _finally_ moved to the proper
parallal port driver model, something I never thought I would see
happen. Good stuff.
- other tiny driver updates and fixes.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big set of char and misc driver patches for 4.21-rc1.
Lots of different types of driver things in here, as this tree seems
to be the "collection of various driver subsystems not big enough to
have their own git tree" lately.
Anyway, some highlights of the changes in here:
- binderfs: is it a rule that all driver subsystems will eventually
grow to have their own filesystem? Binder now has one to handle the
use of it in containerized systems.
This was discussed at the Plumbers conference a few months ago and
knocked into mergable shape very fast by Christian Brauner. Who
also has signed up to be another binder maintainer, showing a
distinct lack of good judgement :)
- binder updates and fixes
- mei driver updates
- fpga driver updates and additions
- thunderbolt driver updates
- soundwire driver updates
- extcon driver updates
- nvmem driver updates
- hyper-v driver updates
- coresight driver updates
- pvpanic driver additions and reworking for more device support
- lp driver updates. Yes really, it's _finally_ moved to the proper
parallal port driver model, something I never thought I would see
happen. Good stuff.
- other tiny driver updates and fixes.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (116 commits)
MAINTAINERS: add another Android binder maintainer
intel_th: msu: Fix an off-by-one in attribute store
stm class: Add a reference to the SyS-T document
stm class: Fix a module refcount leak in policy creation error path
char: lp: use new parport device model
char: lp: properly count the lp devices
char: lp: use first unused lp number while registering
char: lp: detach the device when parallel port is removed
char: lp: introduce list to save port number
bus: qcom: remove duplicated include from qcom-ebi2.c
VMCI: Use memdup_user() rather than duplicating its implementation
char/rtc: Use of_node_name_eq for node name comparisons
misc: mic: fix a DMA pool free failure
ptp: fix an IS_ERR() vs NULL check
genwqe: Fix size check
binder: implement binderfs
binder: fix use-after-free due to ksys_close() during fdget()
bus: fsl-mc: remove duplicated include files
bus: fsl-mc: explicitly define the fsl_mc_command endianness
misc: ti-st: make array read_ver_cmd static, shrinks object size
...
totalram_pages and totalhigh_pages are made static inline function.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We already have the DEFINE_SHOW_ATTRIBUTE.There is no need to define
such a macro,so remove GENWQE_DEBUGFS_RO.Also use DEFINE_SHOW_ATTRIBUTE
to simplify some code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is useful to expose how many times the balloon resets. If it happens
more than very rarely - this is an indication for a problem.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change all the remaining return values to int to avoid mistakes. Reduce
indentation when possible.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for supporting compaction and OOM notification, this
patch reworks the inflate/deflate loops. The main idea is to separate
the allocation, communication with the hypervisor, and the handling of
errors from each other. Doing will allow us to perform concurrent
inflation and deflation, excluding the actual communication with the
hypervisor.
To do so, we need to get rid of the remaining global state that is kept
in the balloon struct, specifically the refuse_list. When the VM
communicates with the hypervisor, it does not free or put back pages
to the balloon list and instead only moves the pages whose status
indicated failure into a refuse_list on the stack. Once the operation
completes, the inflation or deflation functions handle the list
appropriately.
As we do that, we can consolidate the communication with the hypervisor
for both the lock and unlock operations into a single function. We also
reuse the deflation function for popping the balloon.
As a preparation for preventing races, we hold a spinlock when the
communication actually takes place, and use atomic operations for
updating the balloon size. The balloon page list is still racy and will
be handled in the next patch.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To allow the balloon statistics to be updated concurrently, we change
the statistics to be held per core and aggregate it when needed.
To avoid the memory overhead of keeping the statistics per core, and
since it is likely not used by most users, we start updating the
statistics only after the first use. A read-write semaphore is used to
protect the statistics initialization and avoid races. This semaphore is
(and will) be used to protect configuration changes during reset.
While we are at it, address some other issues: change the statistics
update to inline functions instead of define; use ulong for saving the
statistics; and clean the statistics printouts.
Note that this patch changes the format of the outputs. If there are any
automatic tools that use the statistics, they might fail.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As we want to leave as little as possible on the global balloon
structure, to avoid possible future races, we want to get rid sysinfo.
We can actually get the total_ram directly, and simplify the logic of
vmballoon_send_get_target() a little.
While we are doing that, let's return int and avoid mistakes due to
bool/int conversions.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The required change in the balloon size is currently computed in
vmballoon_work(), vmballoon_inflate() and vmballoon_deflate(). Refactor
it to simplify the next patches.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The name of the macro'd VMW_BALLOON_2M_SHIFT is misleading. The value
reflects 2M huge-page order. Unfortunately, we cannot use
HPAGE_PMD_ORDER, since it is not defined when transparent huge-pages are
off, so we need to define our own one.
Rename it to VMW_BALLOON_2M_ORDER. No functional change.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, when the hypervisor rejects a page during lock operation, the
VM treats pages differently according to the error-code: in certain
cases the page is immediately freed, and in others it is put on a
rejection list and only freed later.
The behavior does not make too much sense. If the page is freed
immediately it is very likely to be used again in the next batch of
allocations, and be rejected again.
In addition, for support of compaction and OOM notifiers, we wish to
separate the logic that communicates with the hypervisor (as well as
analyzes the status of each page) from the logic that allocates or free
pages.
Treat all errors the same way, queuing the pages on the refuse list.
Move to the next allocation size (4k) when too many pages are refused.
Free the refused pages when moving to the next size to avoid situations
in which too much memory is waiting to be freed on the refused list.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current abstractions for batch vs single operations seem suboptimal
and complicate the implementation of additional features (OOM,
compaction).
The immediate problem of the current abstractions is that they cause
differences in how operations are handled when batching is on or off.
For example, the refused_alloc counter is not updated when batching is
on. These discrepancies are caused by code redundancies.
Instead, this patch presents three type of operations, according to
whether batching is on or off: (1) add page, (2) communication with the
hypervisor and (3) retrieving the status of a page.
To avoid the overhead of virtual functions, and since we do not expect
additional interfaces for communication with the hypervisor, we use
static keys instead of virtual functions.
Finally, while we are at it, change vmballoon_init_batching() to return
int instead of bool, to be consistent in the return type and avoid
potential coding errors.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Splitting the allocations between sleeping and non-sleeping made some
sort of sense as long as rate-limiting was enabled. Now that it is
removed, we need to decide - either we want sleeping allocations or not.
Since no other Linux balloon driver (hv, Xen, virtio) uses sleeping
allocations, use the same approach.
We do distinguish, however, between 2MB allocations and 4kB allocations
and prevent reclamation on 2MB. In both cases, we avoid using emergency
low-memory pools, as it may cause undesired effects.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The use of accessors for batch entries complicates the code and makes it
less readable. Remove it an instead use bit-fields.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock and unlock code paths are very similar, so avoid the duplicate
code by merging them together.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have a single point, unify the tracing and collecting the
statistics for commands and their failure. While it might somewhat
reduce the control over debugging, it cleans the code a lot.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By inlining the hypercall interface, we can unify several operations
into one central point in the code:
- Updating the target.
- Updating when a reset is needed.
- Update statistics (which will be done later in the patch-set).
- Print debug-messages (although they cannot be enabled as selectively).
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Embarrassingly, the recent fix introduced worse problem than it solved,
causing the balloon not to inflate. The VM informed the hypervisor that
the pages for lock/unlock are sitting in the wrong address, as it used
the page that is used the uninitialized page variable.
Fixes: b23220fe05 ("vmw_balloon: fixing double free when batching mode is off")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removing the GPL wording and replace it with an SPDX tag. The immediate
trigger for doing it now is the need to remove the list of maintainers
from the source file, as the maintainer list changed.
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 33d268ed00 ("VMware balloon: Do not limit the amount of
frees and allocations in non-sleep mode."), the allocations are not
increased, and therefore balloon inflation rate limiting is in practice
broken.
While we can restore rate limiting, in practice we see that it can
result in adverse effect, as the hypervisor throttles down the VM if it
does not respond well enough, or alternatively causes it to perform very
poorly as the host swaps out the VM memory. Throttling the VM down can
even have a cascading effect, in which the VM reclaims memory even
slower and consequentially throttled down even further.
We therefore remove all the rate limiting mechanisms, including the slow
allocation cycles, as they are likely to do more harm than good.
Fixes: 33d268ed00 ("VMware balloon: Do not limit the amount of frees and allocations in non-sleep mode.")
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, when all modules, including VMCI and VMware balloon are built
into the kernel, the initialization of the balloon happens before the
VMCI is probed. As a result, the balloon fails to initialize the VMCI
doorbell, which it uses to get asynchronous requests for balloon size
changes.
The problem can be seen in the logs, in the form of the following
message:
"vmw_balloon: failed to initialize vmci doorbell"
The driver would work correctly but slightly less efficiently, probing
for requests periodically. This patch changes the balloon to be
initialized using late_initcall() instead of module_init() to address
this issue. It does not address a situation in which VMCI is built as a
module and the balloon is built into the kernel.
Fixes: 48e3d668b7 ("VMware balloon: Enable notification via VMCI")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When vmballoon_vmci_init() sets a doorbell using VMCI_DOORBELL_SET, for
some reason it does not consider the status and looks at the result.
However, the hypervisor does not update the result - it updates the
status. This might cause VMCI doorbell not to be enabled, resulting in
degraded performance.
Fixes: 48e3d668b7 ("VMware balloon: Enable notification via VMCI")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the hypervisor sets 2MB batching is on, while batching is cleared,
the balloon code breaks. In this case the legacy mechanism is used with
2MB page. The VM would report a 2MB page is ballooned, and the
hypervisor would only take the first 4KB.
While the hypervisor should not report such settings, make the code more
robust by not enabling 2MB support without batching.
Fixes: 365bd7ef7e ("VMware balloon: Support 2m page ballooning.")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When balloon batching is not supported by the hypervisor, the guest
frame number (GFN) must fit in 32-bit. However, due to a bug, this check
was mistakenly ignored. In practice, when total RAM is greater than
16TB, the balloon does not work currently, making this bug unlikely to
happen.
Fixes: ef0f8f1129 ("VMware balloon: partially inline vmballoon_reserve_page.")
Cc: stable@vger.kernel.org
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep. Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep. The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Get notified immediately when a balloon target is set, instead of waiting for
up to one second.
The up-to 1 second gap could be long enough to cause swapping inside of the
VM that receives the VM.
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Tested-by: Siva Sankar Reddy B <sankars@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unify the behavior of the first start of the balloon and a reset. Also on
unload, declare that the balloon driver does not have any capabilities
anymore.
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2m ballooning significantly reduces the hypervisor side (and guest side)
overhead of ballooning and unballooning.
hypervisor only:
balloon unballoon
4 KB 2 GB/s 2.6 GB/s
2 MB 54 GB/s 767 GB/s
Use 2 MB pages as the hypervisor is alwys 64bit and 2 MB is the smallest
supported super-page size.
The code has to run on older versions of ESX and old balloon drivers run on
newer version of ESX. Hence match the capabilities with the host before 2m
page ballooning could be enabled.
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When VMware's hypervisor requests a VM to reclaim memory this is preferrably done
via ballooning. If the balloon driver does not return memory fast enough, more
drastic methods, such as hypervisor-level swapping are needed. These other methods
cause performance issues, e.g. hypervisor-level swapping requires the hypervisor to
swap in a page syncronously while the virtual CPU is blocked.
Hence it is in the interest of the VM to balloon memory as fast as possible. The
problem with doing this is that the VM might end up doing nothing else than
ballooning and the user might notice that the VM is stalled, esp. when the VM has
only a single virtual CPU.
This is less of a problem if the VM and the hypervisor perform balloon operations
faster. Also the balloon driver yields regularly, hence on a single virtual CPU
the Linux scheduler should be able to properly time-slice between ballooning and
other tasks.
Testing Done: quickly ballooned a lot of pages while wathing if there are any
perceived hickups (periods of non-responsiveness) in the execution of the
linux VM. No such hickups were seen.
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This helps with debugging vmw_balloon behavior, as it is clear what
functionality is enabled.
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of waiting for the next GET_TARGET command, we can react faster
by exploiting the fact that each hypervisor call also returns the
balloon target.
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a new capability to the driver that allow sending 512 pages in
one hypervisor call. This reduce the cost of the driver when reclaiming
memory.
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to extend the balloon protocol, the hypervisor and the guest
driver need to agree on a set of supported functionality to use.
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Philip P. Moltmann <moltmann@vmware.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Greg Kroah-Hartman