public inbox for glibc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug libc/29329] New: hp-timing not correct for graviton
@ 2022-07-07 16:41 juntangc at amazon dot com
2022-07-07 17:50 ` [Bug libc/29329] " fweimer at redhat dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: juntangc at amazon dot com @ 2022-07-07 16:41 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=29329
Bug ID: 29329
Summary: hp-timing not correct for graviton
Product: glibc
Version: unspecified
Status: UNCONFIRMED
Severity: minor
Priority: P2
Component: libc
Assignee: unassigned at sourceware dot org
Reporter: juntangc at amazon dot com
CC: drepper.fsp at gmail dot com
Target Milestone: ---
hp-timing is only used on benchtests today, but it can be used on other things
in the future. It's broken on graviton beacuse the freq we have is 1050000000.
1000000000ULL/1050000000ULL = 0 and thus the difference becomes 0.
The following patch can fix the bug:
```
diff --git a/sysdeps/aarch64/hp-timing.h b/sysdeps/aarch64/hp-timing.h
index f7f7ac7cae..270e0c2e24 100644
--- a/sysdeps/aarch64/hp-timing.h
+++ b/sysdeps/aarch64/hp-timing.h
@@ -41,7 +41,7 @@ typedef uint64_t hp_timing_t;
#define HP_TIMING_DIFF(Diff, Start, End) \
({ hp_timing_t freq; \
__asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \
- (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \
+ (Diff) = (hp_timing_t)((End) - (Start)) * ((1000000000.0) / freq); \
})
#endif /* hp-timing.h */
```
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libc/29329] hp-timing not correct for graviton
2022-07-07 16:41 [Bug libc/29329] New: hp-timing not correct for graviton juntangc at amazon dot com
@ 2022-07-07 17:50 ` fweimer at redhat dot com
2023-01-31 17:12 ` juntangc at amazon dot com
2023-03-08 16:31 ` wdijkstr at arm dot com
2 siblings, 0 replies; 4+ messages in thread
From: fweimer at redhat dot com @ 2022-07-07 17:50 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=29329
--- Comment #1 from Florian Weimer <fweimer at redhat dot com> ---
*** Bug 29330 has been marked as a duplicate of this bug. ***
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libc/29329] hp-timing not correct for graviton
2022-07-07 16:41 [Bug libc/29329] New: hp-timing not correct for graviton juntangc at amazon dot com
2022-07-07 17:50 ` [Bug libc/29329] " fweimer at redhat dot com
@ 2023-01-31 17:12 ` juntangc at amazon dot com
2023-03-08 16:31 ` wdijkstr at arm dot com
2 siblings, 0 replies; 4+ messages in thread
From: juntangc at amazon dot com @ 2023-01-31 17:12 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=29329
--- Comment #2 from Tang, Jun <juntangc at amazon dot com> ---
The proposed patch is
```
diff --git a/sysdeps/aarch64/hp-timing.h b/sysdeps/aarch64/hp-timing.h
index f7f7ac7cae..c699effe6a 100644
--- a/sysdeps/aarch64/hp-timing.h
+++ b/sysdeps/aarch64/hp-timing.h
@@ -41,7 +41,7 @@ typedef uint64_t hp_timing_t;
#define HP_TIMING_DIFF(Diff, Start, End) \
({ hp_timing_t freq; \
__asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \
- (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \
+ (Diff) = (((End) - (Start)) * UINT64_C(1000000000)) / freq; \
})
#endif /* hp-timing.h */
```
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libc/29329] hp-timing not correct for graviton
2022-07-07 16:41 [Bug libc/29329] New: hp-timing not correct for graviton juntangc at amazon dot com
2022-07-07 17:50 ` [Bug libc/29329] " fweimer at redhat dot com
2023-01-31 17:12 ` juntangc at amazon dot com
@ 2023-03-08 16:31 ` wdijkstr at arm dot com
2 siblings, 0 replies; 4+ messages in thread
From: wdijkstr at arm dot com @ 2023-03-08 16:31 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=29329
Wilco <wdijkstr at arm dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Status|UNCONFIRMED |RESOLVED
CC| |wdijkstr at arm dot com
--- Comment #3 from Wilco <wdijkstr at arm dot com> ---
Fixed:
commit 311a7e0256975275d97077f1af338bc9caf0c837
Author: Jun Tang <juntangc@amazon.com>
Date: Wed Feb 22 16:45:59 2023 +0000
AArch64: Fix HP_TIMING_DIFF computation [BZ# 29329]
Fix the computation to allow for cntfrq_el0 being larger than 1GHz.
Assume cntfrq_el0 is a multiple of 1MHz to increase the maximum
interval (1024 seconds at 1GHz).
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-03-08 16:31 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-07 16:41 [Bug libc/29329] New: hp-timing not correct for graviton juntangc at amazon dot com
2022-07-07 17:50 ` [Bug libc/29329] " fweimer at redhat dot com
2023-01-31 17:12 ` juntangc at amazon dot com
2023-03-08 16:31 ` wdijkstr at arm dot com
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).