From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: 'GNU C Library' <libc-alpha@sourceware.org>,
"rafaeleduardoruviaro.christ@asml.com"
<rafaeleduardoruviaro.christ@asml.com>
Subject: aarch64 lacks HP_TIMING support in glibc
Date: Wed, 23 Jun 2021 11:43:28 +0000 [thread overview]
Message-ID: <VE1PR08MB5599A790A65004C303D770DF83089@VE1PR08MB5599.eurprd08.prod.outlook.com> (raw)
Hi Rafael,
> I noticed that aarch64 lacks HP_TIMING support in glibc. Although this architecture has generic timers, glibc is still using the generic hp-timing.h for aarch64.
> I see HP_TIMING support for other architectures. I'd like to know why there is no HP_TIMING support for aarch64?
> Also, if there's planning to support it for aarch64?
I added HP_TIMING support for all targets a while back - this uses fast timers
via the vDSO mechanism. Some targets also have a header with an inline counter.
However it's not an external header and it is hardly used inside GLIBC, so it's
not clear whether it's worth the effort to ensure that cntvct_el0 is never trapped
on AArch64 or just declare the systems that do trap it obsolete.
Cheers,
Wilco
next reply other threads:[~2021-06-23 11:44 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 11:43 Wilco Dijkstra [this message]
2021-06-23 13:26 ` Adhemerval Zanella
2021-06-23 15:19 ` Wilco Dijkstra
2021-06-28 15:49 ` Rafael Eduardo Ruviaro Christ
2021-06-28 19:25 ` Wilco Dijkstra
2021-06-30 13:27 ` Rafael Eduardo Ruviaro Christ
2021-07-02 13:13 ` Wilco Dijkstra
2021-07-02 13:53 ` Adhemerval Zanella
-- strict thread matches above, loose matches on Subject: below --
2021-06-22 18:29 Rafael Eduardo Ruviaro Christ
2021-06-22 18:38 ` Andrew Pinski
2021-06-22 18:57 ` Adhemerval Zanella
2021-06-22 19:27 ` Andreas Schwab
2021-06-22 19:53 ` Adhemerval Zanella
2021-06-22 20:18 ` Andreas Schwab
2021-06-22 20:22 ` Adhemerval Zanella
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