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
21 Jun, 2017
1 commit
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Currently, percpu_counter_add is a wrapper around __percpu_counter_add
which is preempt safe due to explicit calls to preempt_disable. Given
how __ prefix is used in percpu related interfaces, the naming
unfortunately creates the false sense that __percpu_counter_add is
less safe than percpu_counter_add. In terms of context-safety,
they're equivalent. The only difference is that the __ version takes
a batch parameter.Make this a bit more explicit by just renaming __percpu_counter_add to
percpu_counter_add_batch.This patch doesn't cause any functional changes.
tj: Minor updates to patch description for clarity. Cosmetic
indentation updates.Signed-off-by: Nikolay Borisov
Signed-off-by: Tejun Heo
Cc: Chris Mason
Cc: Josef Bacik
Cc: David Sterba
Cc: Darrick J. Wong
Cc: Jan Kara
Cc: Jens Axboe
Cc: linux-mm@kvack.org
Cc: "David S. Miller"
15 Feb, 2016
1 commit
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All are in comments.
Signed-off-by: Bogdan Sikora
Cc:
Cc: Rafael Aquini
Cc: Kent Overstreet
Cc: Jan Kara
[jkosina@suse.cz: more fixup]
Acked-by: Rafael Aquini
Signed-off-by: Jiri Slaby
Signed-off-by: Jiri Kosina
08 Sep, 2014
2 commits
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Percpu allocator now supports allocation mask. Add @gfp to
[flex_]proportions init functions so that !GFP_KERNEL allocation masks
can be used with them too.This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo
Reviewed-by: Jan Kara
Cc: Peter Zijlstra -
Percpu allocator now supports allocation mask. Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion. This is the one with
the most users. Other percpu data structures are a lot easier to
convert.This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo
Acked-by: Jan Kara
Acked-by: "David S. Miller"
Cc: x86@kernel.org
Cc: Jens Axboe
Cc: "Theodore Ts'o"
Cc: Alexander Viro
Cc: Andrew Morton
25 Sep, 2012
1 commit
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When racing with CPU hotplug, percpu_counter_sum() can return negative
values for the number of observed events.This confuses fprop_new_period(), which uses unsigned type and as a
result number of events is set to big *positive* number. From that
moment on, things go pear shaped and can result e.g. in division by
zero as denominator is later truncated to 32-bits.This bug causes a divide-by-zero oops in bdi_dirty_limit() in Borislav's
3.6.0-rc6 based kernel.Fix the issue by using a signed type in fprop_new_period(). That makes
us bail out from the function without doing anything (mistakenly)
thinking there are no events to age. That makes aging somewhat
inaccurate but getting accurate data would be rather hard.Signed-off-by: Jan Kara
Reported-by: Borislav Petkov
Reported-by: Srivatsa S. Bhat
Cc: Wu Fengguang
Cc: Peter Zijlstra
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Jun, 2012
2 commits
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When percpu counter function in fprop_new_period() is interrupted by an
interrupt while holding counter lock, it can cause deadlock when the
interrupt wants to take the lock as well. Fix the problem by disabling
interrupts when calling percpu counter functions.Signed-off-by: Jan Kara
Signed-off-by: Fengguang Wu -
Implement code computing proportions of events of different type (like code in
lib/proportions.c) but allowing periods to have different lengths. This allows
us to have aging periods of fixed wallclock time which gives better proportion
estimates given the hugely varying throughput of different devices - previous
measuring of aging period by number of events has the problem that a reasonable
period length for a system with low-end USB stick is not a reasonable period
length for a system with high-end storage array resulting either in too slow
proportion updates or too fluctuating proportion updates.Acked-by: Peter Zijlstra
Signed-off-by: Jan Kara
Signed-off-by: Fengguang Wu