KMALLOC_MAX_CACHE_SIZE is 32-bit so is the largest kmalloc cache size.
Christoph said:
:
: Ok SLABs maximum allocation size is limited to 32M (see
: include/linux/slab.h:
:
: #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
: (MAX_ORDER + PAGE_SHIFT - 1) : 25)
:
: And SLUB/SLOB pass all larger requests to the page allocator anyways.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexey Dobriyan <[email protected]>
Acked-by: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
kmalloc_index() return index into an array of kmalloc kmem caches,
therefore should be unsigned.
Space savings with SLUB on trimmed down .config:
add/remove: 0/1 grow/shrink: 6/56 up/down: 85/-557 (-472)
Function old new delta
calculate_sizes 924 983 +59
on_freelist 589 604 +15
init_cache_random_seq 122 127 +5
ext4_mb_init 1206 1210 +4
slab_pad_check.part 270 271 +1
cpu_partial_store 112 113 +1
usersize_show 28 27 -1
...
new_slab 1871 1837 -34
slab_order 204 - -204
This patch start a series of converting SLUB (mostly) to "unsigned int".
1) Most integers in the code are in fact unsigned entities: array
indexes, lengths, buffer sizes, allocation orders. It is therefore
better to use unsigned variables
2) Some integers in the code are either "size_t" or "unsigned long" for
no reason.
size_t usually comes from people trying to maintain type correctness
and figuring out that "sizeof" operator returns size_t or
memset/memcpy takes size_t so should everything passed to it.
However the number of 4GB+ objects in the kernel is very small. Most,
if not all, dynamically allocated objects with kmalloc() or
kmem_cache_create() aren't actually big. Maintaining wide types
doesn't do anything.
64-bit ops are bigger than 32-bit on our beloved x86_64,
so try to not use 64-bit where it isn't necessary
(read: everywhere where integers are integers not pointers)
3) in case of SLAB allocators, there are additional limitations
*) page->inuse, page->objects are only 16-/15-bit,
*) cache size was always 32-bit
*) slab orders are small, order 20 is needed to go 64-bit on x86_64
(PAGE_SIZE << order)
Basically everything is 32-bit except kmalloc(1ULL<<32) which gets
shortcut through page allocator.
Christoph said:
:
: That changes with large base page size on power and ARM64 f.e. but then
: we do not want to encourage larger allocations through slab anyways.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexey Dobriyan <[email protected]>
Acked-by: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
When SLUB_DEBUG catches some issues, it prints all the required debug
info. However, in a few cases where allocation and free of the object
has happened in a very short time, 'age' might be misleading. See the
example below:
=============================================================================
BUG kmalloc-256 (Tainted: G W O ): Poison overwritten
-----------------------------------------------------------------------------
...
INFO: Allocated in binder_transaction+0x4b0/0x2448 age=731 cpu=3 pid=5314
...
INFO: Freed in binder_free_transaction+0x2c/0x58 age=735 cpu=6 pid=2079
...
Object fffffff14956a870: 6b 6b 6b 6b 6b 6b 6b 6b 67 6b 6b 6b 6b 6b 6b a5 kkkkkkkkgkkkk
In this case, object got freed later but 'age' shows otherwise. This
could be because, while printing this info, we print allocation traces
first and free traces thereafter. In between, if we get schedule out or
jiffies increment, (jiffies - t->when) could become meaningless.
Use the jitter free reference to calculate age.
New output will exactly be same. 'age' is still staying with single
jiffies ref in both prints.
Change-Id: I0846565807a4229748649bbecb1ffb743d71fcd8
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Chintan Pandya <[email protected]>
Acked-by: Christoph Lameter <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
When changing the size of a block device, its all caches are freed.
It's necessary on shrinking to prevent spurious I/Os to the disappeared
region. However, on expanding, such kind of I/Os doesn't happen.
Similar things can be considered for btrfs filesystem resize and
resize2fs, but they are designed not to drop caches when expanding.
Therefore this patch removes unnecessary cache drop.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Shunki Fujita <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jan Kara <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
When the user uses some syscall, for example mmap(v9fs_file_mmap), it
will not update atime even if user's was set mnt_flags without
MNT_NOATIME, because v9fs defaults to settine SB_NOATIME in
v9fs_set_super.
For supporting access time updating when the user mounts with relatime,
we should not set SB_NOATIME by default.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Yiwen Jiang <[email protected]>
Reviewed-by: Greg Kurz <[email protected]>
Cc: Eric Van Hensbergen <[email protected]>
Cc: Ron Minnich <[email protected]>
Cc: Latchesar Ionkov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
If the exported filesystem dir on 9p server doesn't maintain accurate
i_nlink count, e.g. always reports i_nlink as 1, then 9p should not
maintain nlink count either, otherwise drop_link would report warning
with i_nlink being zero.
For example:
- overlayfs sets nlink to 1 for merged dir
- ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has
more than EXT4_LINK_MAX (65000) links.
In this case, everytime a stat(2) call (getattr) on such exported dirs
on 9p client side, the i_nlink gets reset to 1, then operations like
rmdir(2), unlink(2) and rename(2) would cause the dir nlink to go to
zero (then negative), which results in warnings in drop_nlink() and/or
inc_nlink() calls.
This can be reproduced easily as the following steps:
- export a merged overlayfs dir via qemu virtfs to guest
- mount the exported virtfs in guest
- create two sub-directories in the root dir of the mounted 9pfs
- stat the root dir of 9pfs, this resets nlink to 1
- remove all subdirs, the second unlink/rmdir would trigger warning
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1284 at fs/inode.c:282 drop_nlink+0x3e/0x50
...
Call Trace:
dump_stack+0x63/0x81
__warn+0xcb/0xf0
warn_slowpath_null+0x1d/0x20
drop_nlink+0x3e/0x50
v9fs_remove+0xaa/0x130 [9p]
v9fs_vfs_rmdir+0x13/0x20 [9p]
vfs_rmdir+0xb7/0x130
do_rmdir+0x1b8/0x230
SyS_unlinkat+0x22/0x30
do_syscall_64+0x67/0x180
---[ end trace 43758d8ba91e603b ]---
Fix it by leaving i_nlink to be 1 and don't drop nlink if a directory
has nlink <= 2, which indicates that the underlying exported fs doesn't
maintain nlink count accurately. This follows what ext4 does in
ext4_dec_count().
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Eryu Guan <[email protected]>
Reviewed-by: Yiwen Jiang <[email protected]>
Tested-by: Roman Kapl <[email protected]>
Cc: Caspar Zhang <[email protected]>
Cc: Eric Van Hensbergen <[email protected]>
Cc: Ron Minnich <[email protected]>
Cc: Latchesar Ionkov <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
If it was interrupted by a signal, the 9p client may need to send some
more requests to the server for cleanup before returning to userspace.
To avoid such a last minute request to be interrupted right away, the
client memorizes if a signal is pending, clears TIF_SIGPENDING, handles
the request and calls recalc_sigpending() before returning.
Unfortunately, if the transmission of this cleanup request fails for any
reason, the transport returns an error and the client propagates it
right away, without calling recalc_sigpending().
This ends up with -ERESTARTSYS from the initially interrupted request
crawling up to syscall exit, with TIF_SIGPENDING cleared by the cleanup
request. The specific signal handling code, which is responsible for
converting -ERESTARTSYS to -EINTR is not called, and userspace receives
the confusing errno value:
open: Unknown error 512 (512)
This is really hard to hit in real life. I discovered the issue while
working on hot-unplug of a virtio-9p-pci device with an instrumented
QEMU allowing to control request completion.
Both p9_client_zc_rpc() and p9_client_rpc() functions have this buggy
error path actually. Their code flow is a bit obscure and the best
thing to do would probably be a full rewrite: to really ensure this
situation of clearing TIF_SIGPENDING and returning -ERESTARTSYS can
never happen.
But given the general lack of interest for the 9p code, I won't risk
breaking more things. So this patch simply fixes the buggy paths in
both functions with a trivial label+goto.
Thanks to Laurent Dufour for his help and suggestions on how to find the
root cause and how to fix it.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kurz <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Reviewed-by: Yiwen Jiang <[email protected]>
Cc: Eric Van Hensbergen <[email protected]>
Cc: Ron Minnich <[email protected]>
Cc: Latchesar Ionkov <[email protected]>
Cc: David Miller <[email protected]>
Cc: Laurent Dufour <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Patch series "ocfs2: use kobject for online file check", v3.
Use embedded kobject mechanism for online file check feature, this will
avoid to use a global list to save/search per-device online file check
related data. The changed code is based on Goldwyn Rodrigues's patches
and ext4 fs code, there is not any new features added, except some very
small fixes during this code refactoring. Second, the code change does
not affect the underlying file check code. Thank Goldwyn very much.
Compare with second version, add more comments in the patch
descriptions, to make sure each modification is mentioned. Compare with
first version, split the code change into four patches, make sure each
patch will not bring ocfs2 kernel modules compiling errors.
This patch (of 3):
Move some definitions to header file, which will be referenced by other
source files when kobject mechanism is introduced.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Gang He <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Joseph Qi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Wait for dlm recovery done when migrating all lock resources in case that
new lock resource left after leaving dlm domain. And the left lock
resource will cause other nodes BUG.
NodeA NodeB NodeC
umount:
dlm_unregister_domain()
dlm_migrate_all_locks()
NodeB down
do recovery for NodeB
and collect a new lockres
form other live nodes:
dlm_do_recovery
dlm_remaster_locks
dlm_request_all_locks:
dlm_mig_lockres_handler
dlm_new_lockres
__dlm_insert_lockres
at last NodeA become the
master of the new lockres
and leave domain:
dlm_leave_domain()
mount:
dlm_join_domain()
touch file and request
for the owner of the new
lockres, but all the
other nodes said 'NO',
so NodeC decide to be
the owner, and send do
assert msg to other
nodes:
dlmlock()
dlm_get_lock_resource()
dlm_do_assert_master()
other nodes receive the msg
and found two masters exist.
at last cause BUG in
dlm_assert_master_handler()
-->BUG();
Link: http://lkml.kernel.org/r/[email protected]
Fixes: bc9838c4d4 ("dlm: allow dlm do recovery during shutdown")
Signed-off-by: Jun Piao <[email protected]>
Reviewed-by: Alex Chen <[email protected]>
Reviewed-by: Yiwen Jiang <[email protected]>
Acked-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
We should not handle migrate lockres if we are already in
'DLM_CTXT_IN_SHUTDOWN', as that will cause lockres remains after leaving
dlm domain. At last other nodes will get stuck into infinite loop when
requsting lock from us.
The problem is caused by concurrency umount between nodes. Before
receiveing N1's DLM_BEGIN_EXIT_DOMAIN_MSG, N2 has picked up N1 as the
migrate target. So N2 will continue sending lockres to N1 even though
N1 has left domain.
N1 N2 (owner)
touch file
access the file,
and get pr lock
begin leave domain and
pick up N1 as new owner
begin leave domain and
migrate all lockres done
begin migrate lockres to N1
end leave domain, but
the lockres left
unexpectedly, because
migrate task has passed
[[email protected]: v3]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jun Piao <[email protected]>
Reviewed-by: Yiwen Jiang <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Reviewed-by: Changwei Ge <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This is a fix for a regression in 32 bit kernels caused by an invalid
check for pgoff overflow in hugetlbfs mmap setup. The check incorrectly
specified that the size of a loff_t was the same as the size of a long.
The regression prevents mapping hugetlbfs files at offsets greater than
4GB on 32 bit kernels.
On 32 bit kernels conversion from a page based unsigned long can not
overflow a loff_t byte offset. Therefore, skip this check if
sizeof(unsigned long) != sizeof(loff_t).
Link: http://lkml.kernel.org/r/[email protected]
Fixes: 63489f8e82 ("hugetlbfs: check for pgoff value overflow")
Reported-by: Dan Rue <[email protected]>
Signed-off-by: Mike Kravetz <[email protected]>
Tested-by: Anders Roxell <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Yisheng Xie <[email protected]>
Cc: "Kirill A . Shutemov" <[email protected]>
Cc: Nic Losby <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Calling __stack_chk_guard_setup() in decompress_kernel() is too late
that stack checking always fails for decompress_kernel() itself. So
remove __stack_chk_guard_setup() and initialize __stack_chk_guard before
we call decompress_kernel().
Original code comes from ARM but also used for MIPS and SH, so fix them
together. If without this fix, compressed booting of these archs will
fail because stack checking is enabled by default (>=4.16).
Link: http://lkml.kernel.org/r/[email protected]
Fixes: 8779657d29 ("stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONG")
Signed-off-by: Huacai Chen <[email protected]>
Acked-by: James Hogan <[email protected]>
Acked-by: Kees Cook <[email protected]>
Acked-by: Rich Felker <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Russell King <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
The main addition this time around is the new ARM "SCMI" framework,
which is the latest in a series of standards coming from ARM to do power
management in a platform independent way. This has been through many
review cycles, and it relies on a rather interesting way of using the
mailbox subsystem, but in the end I agreed that Sudeep's version was
the best we could do after all.
Other changes include:
- the ARM CCN driver is moved out of drivers/bus into drivers/perf,
which makes more sense. Similarly, the performance monitoring
portion of the CCI driver are moved the same way and cleaned up
a little more.
- a series of updates to the SCPI framework
- support for the Mediatek mt7623a SoC in drivers/soc
- support for additional NVIDIA Tegra hardware in drivers/soc
- a new reset driver for Socionext Uniphier
- lesser bug fixes in drivers/soc, drivers/tee, drivers/memory, and
drivers/firmware and drivers/reset across platforms
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Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Arnd Bergmann:
"The main addition this time around is the new ARM "SCMI" framework,
which is the latest in a series of standards coming from ARM to do
power management in a platform independent way.
This has been through many review cycles, and it relies on a rather
interesting way of using the mailbox subsystem, but in the end I
agreed that Sudeep's version was the best we could do after all.
Other changes include:
- the ARM CCN driver is moved out of drivers/bus into drivers/perf,
which makes more sense. Similarly, the performance monitoring
portion of the CCI driver are moved the same way and cleaned up a
little more.
- a series of updates to the SCPI framework
- support for the Mediatek mt7623a SoC in drivers/soc
- support for additional NVIDIA Tegra hardware in drivers/soc
- a new reset driver for Socionext Uniphier
- lesser bug fixes in drivers/soc, drivers/tee, drivers/memory, and
drivers/firmware and drivers/reset across platforms"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (87 commits)
reset: uniphier: add ethernet reset control support for PXs3
reset: stm32mp1: Enable stm32mp1 reset driver
dt-bindings: reset: add STM32MP1 resets
reset: uniphier: add Pro4/Pro5/PXs2 audio systems reset control
reset: imx7: add 'depends on HAS_IOMEM' to fix unmet dependency
reset: modify the way reset lookup works for board files
reset: add support for non-DT systems
clk: scmi: use devm_of_clk_add_hw_provider() API and drop scmi_clocks_remove
firmware: arm_scmi: prevent accessing rate_discrete uninitialized
hwmon: (scmi) return -EINVAL when sensor information is unavailable
amlogic: meson-gx-socinfo: Update soc ids
soc/tegra: pmc: Use the new reset APIs to manage reset controllers
soc: mediatek: update power domain data of MT2712
dt-bindings: soc: update MT2712 power dt-bindings
cpufreq: scmi: add thermal dependency
soc: mediatek: fix the mistaken pointer accessed when subdomains are added
soc: mediatek: add SCPSYS power domain driver for MediaTek MT7623A SoC
soc: mediatek: avoid hardcoded value with bus_prot_mask
dt-bindings: soc: add header files required for MT7623A SCPSYS dt-binding
dt-bindings: soc: add SCPSYS binding for MT7623 and MT7623A SoC
...
