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| author | Thomas Gleixner <[email protected]> | 2024-10-15 12:08:39 +0200 |
|---|---|---|
| committer | Thomas Gleixner <[email protected]> | 2024-10-25 19:49:13 +0200 |
| commit | 6860d28ccb2390b4eeda32ab2ce7eb10f71921e1 (patch) | |
| tree | 6e1e71cb973d25dc099d54df1f08f96a66db952e /tools/perf/scripts/python/task-analyzer.py | |
| parent | c2a329566a3d5a638061733f232c40379235931d (diff) | |
timekeeping: Reorder struct timekeeper
struct timekeeper is ordered suboptimal vs. cachelines. The layout,
including the preceding seqcount (see struct tk_core in timekeeper.c) is:
cacheline 0: seqcount, tkr_mono
cacheline 1: tkr_raw, xtime_sec
cacheline 2: ktime_sec ... tai_offset, internal variables
cacheline 3: next_leap_ktime, raw_sec, internal variables
cacheline 4: internal variables
So any access to via ktime_get*() except for access to CLOCK_MONOTONIC_RAW
will use either cachelines 0 + 1 or cachelines 0 + 2. Access to
CLOCK_MONOTONIC_RAW uses cachelines 0 + 1 + 3.
Reorder the members so that the result is more efficient:
cacheline 0: seqcount, tkr_mono
cacheline 1: xtime_sec, ktime_sec ... tai_offset
cacheline 2: tkr_raw, raw_sec
cacheline 3: internal variables
cacheline 4: internal variables
That means ktime_get*() will access cacheline 0 + 1 and CLOCK_MONOTONIC_RAW
access will use cachelines 0 + 2.
Update kernel-doc and fix formatting issues while at it. Also fix a typo
in struct tk_read_base kernel-doc.
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Anna-Maria Behnsen <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: John Stultz <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Diffstat (limited to 'tools/perf/scripts/python/task-analyzer.py')
0 files changed, 0 insertions, 0 deletions