06 May, 2021
2 commits
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Since CMA is getting used more widely, it's more important to keep
monitoring CMA statistics for system health since it's directly related to
user experience.This patch introduces sysfs statistics for CMA, in order to provide some
basic monitoring of the CMA allocator.* the number of CMA page successful allocations
* the number of CMA page allocation failuresThese two values allow the user to calcuate the allocation
failure rate for each CMA area.e.g.)
/sys/kernel/mm/cma/WIFI/alloc_pages_[success|fail]
/sys/kernel/mm/cma/SENSOR/alloc_pages_[success|fail]
/sys/kernel/mm/cma/BLUETOOTH/alloc_pages_[success|fail]The cma_stat was intentionally allocated by dynamic allocation
to harmonize with kobject lifetime management.
https://lore.kernel.org/linux-mm/YCOAmXqt6dZkCQYs@kroah.com/Link: https://lkml.kernel.org/r/20210324230759.2213957-1-minchan@kernel.org
Link: https://lore.kernel.org/linux-mm/20210316100433.17665-1-colin.king@canonical.com/
Signed-off-by: Minchan Kim
Signed-off-by: Colin Ian KingTested-by: Dmitry Osipenko
Reviewed-by: Dmitry Osipenko
Reviewed-by: Greg Kroah-Hartman
Reviewed-by: John Hubbard
Tested-by: Anders Roxell
Cc: Suren Baghdasaryan
Cc: John Dias
Cc: Matthew Wilcox (Oracle)
Cc: Colin Ian King
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "make hugetlb put_page safe for all calling contexts", v5.
This effort is the result a recent bug report [1]. Syzbot found a
potential deadlock in the hugetlb put_page/free_huge_page_path. WARNING:
SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected Since the
free_huge_page_path already has code to 'hand off' page free requests to a
workqueue, a suggestion was proposed to make the in_irq() detection
accurate by always enabling PREEMPT_COUNT [2]. The outcome of that
discussion was that the hugetlb put_page path (free_huge_page) path should
be properly fixed and safe for all calling contexts.[1] https://lore.kernel.org/linux-mm/000000000000f1c03b05bc43aadc@google.com/
[2] http://lkml.kernel.org/r/20210311021321.127500-1-mike.kravetz@oracle.comThis patch (of 8):
cma_release is currently a sleepable operatation because the bitmap
manipulation is protected by cma->lock mutex. Hugetlb code which relies
on cma_release for CMA backed (giga) hugetlb pages, however, needs to be
irq safe.The lock doesn't protect any sleepable operation so it can be changed to a
(irq aware) spin lock. The bitmap processing should be quite fast in
typical case but if cma sizes grow to TB then we will likely need to
replace the lock by a more optimized bitmap implementation.Link: https://lkml.kernel.org/r/20210409205254.242291-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20210409205254.242291-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz
Acked-by: Michal Hocko
Reviewed-by: David Hildenbrand
Acked-by: Roman Gushchin
Cc: Shakeel Butt
Cc: Oscar Salvador
Cc: Muchun Song
Cc: David Rientjes
Cc: Miaohe Lin
Cc: Peter Zijlstra
Cc: Matthew Wilcox
Cc: HORIGUCHI NAOYA
Cc: "Aneesh Kumar K . V"
Cc: Waiman Long
Cc: Peter Xu
Cc: Mina Almasry
Cc: Hillf Danton
Cc: Joonsoo Kim
Cc: Barry Song
Cc: Will Deacon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Sep, 2020
1 commit
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CMA_MAX_NAME should be visible to CMA's users as they might need it to set
the name of CMA areas and avoid hardcoding the size locally.
So this patch moves CMA_MAX_NAME from local header file to include/linux
header file and removes the hardcode in both hugetlb.c and contiguous.c.Signed-off-by: Barry Song
Signed-off-by: Christoph Hellwig
13 Aug, 2020
1 commit
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Patch series "mm: fix the names of general cma and hugetlb cma", v2.
The current code of CMA can only work when users pass a const string as
name parameter. we need to fix the way to handle names in CMA. On the
other hand, to avoid name conflicts after enabling CMA_DEBUGFS, each
hugetlb should get a different CMA name.This patch (of 2):
If users give a name saved in stack, the current code will generate magic
pointer. if users don't give a name(NULL), kasprintf() will always return
NULL as we are at the early stage. that means cma_init_reserved_mem()
will return -ENOMEM if users set name parameter as NULL.[natechancellor@gmail.com: return cma->name directly in cma_get_name]
Link: https://github.com/ClangBuiltLinux/linux/issues/1063
Link: http://lkml.kernel.org/r/20200623015840.621964-1-natechancellor@gmail.comSigned-off-by: Barry Song
Signed-off-by: Nathan Chancellor
Signed-off-by: Andrew Morton
Reviewed-by: Mike Kravetz
Acked-by: Roman Gushchin
Link: http://lkml.kernel.org/r/20200616223131.33828-2-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds
11 Jul, 2020
1 commit
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debugfs_create_u32_array() allocates a small structure to wrap
the data and size information about the array. If users ever
try to remove the file this leads to a leak since nothing ever
frees this wrapper.That said there are no upstream users of debugfs_create_u32_array()
that'd remove a u32 array file (we only have one u32 array user in
CMA), so there is no real bug here.Make callers pass a wrapper they allocated. This way the lifetime
management of the wrapper is on the caller, and we can avoid the
potential leak in debugfs.CC: Chucheng Luo
Signed-off-by: Jakub Kicinski
Reviewed-by: Greg Kroah-Hartman
Signed-off-by: David S. Miller
02 Nov, 2017
1 commit
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Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
19 Apr, 2017
1 commit
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Frameworks that may want to enumerate CMA heaps (e.g. Ion) will find it
useful to have an explicit name attached to each region. Store the name
in each CMA structure.Signed-off-by: Laura Abbott
Signed-off-by: Greg Kroah-Hartman
15 Aug, 2015
1 commit
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cma_bitmap_maxno() was marked as static and not static inline, which can
cause warnings about this function not being used if this file is included
in a file that does not call that function, and violates the conventions
used elsewhere. The two options are to move the function implementation
back to mm/cma.c or make it inline here, and it's simple enough for the
latter to make sense.Signed-off-by: Gregory Fong
Cc: Joonsoo Kim
Cc: Sasha Levin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Apr, 2015
2 commits
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Provides a userspace interface to trigger a CMA allocation.
Usage:
echo [pages] > alloc
This would provide testing/fuzzing access to the CMA allocation paths.
Signed-off-by: Sasha Levin
Acked-by: Joonsoo Kim
Cc: Marek Szyprowski
Cc: Laura Abbott
Cc: Konrad Rzeszutek Wilk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I've noticed that there is no interfaces exposed by CMA which would let me
fuzz what's going on in there.This small patchset exposes some information out to userspace, plus adds
the ability to trigger allocation and freeing from userspace.This patch (of 3):
Implement a simple debugfs interface to expose information about CMA areas
in the system.Useful for testing/sanity checks for CMA since it was impossible to
previously retrieve this information in userspace.Signed-off-by: Sasha Levin
Acked-by: Joonsoo Kim
Cc: Marek Szyprowski
Cc: Laura Abbott
Cc: Konrad Rzeszutek Wilk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
