lkml.org 
[lkml]   [2020]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 7/7] tools headers UAPI: Update tools's copy of linux/perf_event.h
Date
To get the changes in the commit:

"perf: Add perf_event_mmap_page::cap_user_time_short ABI"

This update is a prerequisite to add support for short clock counters
related ABI extension.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
tools/include/uapi/linux/perf_event.h | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 7b2d6fc9e6ed..21a1edd08cbe 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -532,9 +532,10 @@ struct perf_event_mmap_page {
cap_bit0_is_deprecated : 1, /* Always 1, signals that bit 0 is zero */

cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */
- cap_user_time : 1, /* The time_* fields are used */
+ cap_user_time : 1, /* The time_{shift,mult,offset} fields are used */
cap_user_time_zero : 1, /* The time_zero field is used */
- cap_____res : 59;
+ cap_user_time_short : 1, /* the time_{cycle,mask} fields are used */
+ cap_____res : 58;
};
};

@@ -593,13 +594,29 @@ struct perf_event_mmap_page {
* ((rem * time_mult) >> time_shift);
*/
__u64 time_zero;
+
__u32 size; /* Header size up to __reserved[] fields. */
+ __u32 __reserved_1;
+
+ /*
+ * If cap_usr_time_short, the hardware clock is less than 64bit wide
+ * and we must compute the 'cyc' value, as used by cap_usr_time, as:
+ *
+ * cyc = time_cycles + ((cyc - time_cycles) & time_mask)
+ *
+ * NOTE: this form is explicitly chosen such that cap_usr_time_short
+ * is a correction on top of cap_usr_time, and code that doesn't
+ * know about cap_usr_time_short still works under the assumption
+ * the counter doesn't wrap.
+ */
+ __u64 time_cycles;
+ __u64 time_mask;

/*
* Hole for extension of the self monitor capabilities
*/

- __u8 __reserved[118*8+4]; /* align to 1k. */
+ __u8 __reserved[116*8]; /* align to 1k. */

/*
* Control data for the mmap() data buffer.
--
2.17.1
\
 
 \ /
  Last update: 2020-07-16 07:14    [W:0.786 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site