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| author | Nikolay Borisov <[email protected]> | 2020-01-30 14:59:44 +0200 |
|---|---|---|
| committer | David Sterba <[email protected]> | 2020-03-23 17:01:43 +0100 |
| commit | 2992df73268f78ec9281692b9b44ae92f3933b54 (patch) | |
| tree | 317bf92dc9d5546f91945f21d23eb0fd2e656bce /tools/perf/scripts/python/syscall-counts-by-pid.py | |
| parent | fd8efa818c55300ffb69c11e573c5ed18cda541c (diff) | |
btrfs: Implement DREW lock
A (D)ouble (R)eader (W)riter (E)xclustion lock is a locking primitive
that allows to have multiple readers or multiple writers but not
multiple readers and writers holding it concurrently.
The code is factored out from the existing open-coded locking scheme
used to exclude pending snapshots from nocow writers and vice-versa.
Current implementation actually favors Readers (that is snapshot
creaters) to writers (nocow writers of the filesystem).
The API provides lock/unlock/trylock for reads and writes.
Formal specification for TLA+ provided by Valentin Schneider is at
https://lore.kernel.org/linux-btrfs/[email protected]/
Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/syscall-counts-by-pid.py')
0 files changed, 0 insertions, 0 deletions