78efa7b411
When users pass the option '--timestamp' or '-T' in the record command,
all events will set the PERF_SAMPLE_TIME bit in the attribution. In
this case, the AUX event will record the kernel timestamp, but it
doesn't mean Arm CoreSight enables timestamp packets in its hardware
tracing.
If the option '--timestamp' or '-T' is set, this patch always enables
Arm CoreSight timestamp, as a result, the bit 28 in event's config is to
be set.
Before:
# perf record -e cs_etm// --per-thread --timestamp -- ls
# perf script --header-only
...
# event : name = cs_etm//, , id = { 69 }, type = 12, size = 136,
config = 0, { sample_period, sample_freq } = 1,
sample_type = IP|TID|TIME|CPU|IDENTIFIER, read_format = ID|LOST,
disabled = 1, enable_on_exec = 1, sample_id_all = 1, exclude_guest = 1
...
After:
# perf record -e cs_etm// --per-thread --timestamp -- ls
# perf script --header-only
...
# event : name = cs_etm//, , id = { 49 }, type = 12, size = 136,
config = 0x10000000, { sample_period, sample_freq } = 1,
sample_type = IP|TID|TIME|CPU|IDENTIFIER, read_format = ID|LOST,
disabled = 1, enable_on_exec = 1, sample_id_all = 1, exclude_guest = 1
...
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20231014074159.1667880-3-leo.yan@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.