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From: "Okanovic, Haris" <harisokn@amazon.com>
To: "cl@gentwo.org" <cl@gentwo.org>
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Subject: Re: [PATCH 3/5] arm64: refactor delay() to enable polling for value
Date: Wed, 6 Nov 2024 17:42:38 +0000	[thread overview]
Message-ID: <193a81555a87a6d499fbe889406eeb2014465ec5.camel@amazon.com> (raw)
In-Reply-To: <efd92a03-f5a9-ba9b-338f-b9a5ad93174f@gentwo.org>

On Tue, 2024-11-05 at 11:42 -0800, Christoph Lameter (Ampere) wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> On Tue, 5 Nov 2024, Haris Okanovic wrote:
> 
> > -#define USECS_TO_CYCLES(time_usecs)                  \
> > -     xloops_to_cycles((time_usecs) * 0x10C7UL)
> > -
> > -static inline unsigned long xloops_to_cycles(unsigned long xloops)
> > +static inline u64 xloops_to_cycles(u64 xloops)
> >  {
> >       return (xloops * loops_per_jiffy * HZ) >> 32;
> >  }
> > 
> > -void __delay(unsigned long cycles)
> > +#define USECS_TO_XLOOPS(time_usecs) \
> > +     ((time_usecs) * 0x10C7UL)
> > +
> > +#define USECS_TO_CYCLES(time_usecs) \
> > +     xloops_to_cycles(USECS_TO_XLOOPS(time_usecs))
> > +
> 
> 
> > +#define NSECS_TO_XLOOPS(time_nsecs) \
> > +     ((time_nsecs) * 0x10C7UL)
> 
> The constant here is the same value as for microseconds. If I remember
> correctly its 5UL for nanoseconds.
> 

You're right, good catch. Should be `nsecs * 0x5UL` per old code.


  reply	other threads:[~2024-11-06 17:43 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-25 23:24 [PATCH v8 00/11] Enable haltpoll on arm64 Ankur Arora
2024-09-25 23:24 ` [PATCH v8 01/11] cpuidle/poll_state: poll via smp_cond_load_relaxed() Ankur Arora
2024-10-15 12:04   ` Catalin Marinas
2024-10-15 16:42     ` Christoph Lameter (Ampere)
2024-10-15 16:50       ` Catalin Marinas
2024-10-15 17:17         ` Christoph Lameter (Ampere)
2024-10-15 17:40           ` Catalin Marinas
2024-10-15 21:53             ` Ankur Arora
2024-10-15 22:28               ` Christoph Lameter (Ampere)
2024-10-16  7:06                 ` Ankur Arora
2024-10-17 16:54                   ` Christoph Lameter (Ampere)
2024-10-17 18:36                     ` Ankur Arora
2024-10-15 22:40               ` Christoph Lameter (Ampere)
2024-10-16  9:54                 ` Catalin Marinas
2024-10-17 16:56                   ` Christoph Lameter (Ampere)
2024-10-17 18:15                     ` Catalin Marinas
2024-10-17 19:34                       ` Ankur Arora
2024-10-15 21:32     ` Ankur Arora
2024-10-16  6:20       ` maobibo
2024-10-16 10:06       ` Catalin Marinas
2024-10-16 15:13     ` Okanovic, Haris
2024-10-16 17:04       ` Ankur Arora
2024-10-16 18:04         ` Okanovic, Haris
2024-10-17 14:01       ` Catalin Marinas
2024-10-17 22:47         ` Ankur Arora
2024-10-18 11:05           ` Catalin Marinas
2024-10-18 19:00             ` Ankur Arora
2024-10-21 12:02               ` Catalin Marinas
2024-09-25 23:24 ` [PATCH v8 02/11] cpuidle: rename ARCH_HAS_CPU_RELAX to ARCH_HAS_OPTIMIZED_POLL Ankur Arora
2024-09-25 23:24 ` [PATCH v8 03/11] Kconfig: move ARCH_HAS_OPTIMIZED_POLL to arch/Kconfig Ankur Arora
2024-09-25 23:24 ` [PATCH v8 04/11] cpuidle-haltpoll: define arch_haltpoll_want() Ankur Arora
2024-09-25 23:24 ` [PATCH v8 05/11] governors/haltpoll: drop kvm_para_available() check Ankur Arora
2024-09-25 23:24 ` [PATCH v8 06/11] cpuidle-haltpoll: condition on ARCH_CPUIDLE_HALTPOLL Ankur Arora
2024-09-25 23:24 ` [PATCH v8 07/11] arm64: define TIF_POLLING_NRFLAG Ankur Arora
2024-09-25 23:24 ` [PATCH v8 08/11] arm64: idle: export arch_cpu_idle Ankur Arora
2024-09-25 23:24 ` [PATCH v8 09/11] arm64: select ARCH_HAS_OPTIMIZED_POLL Ankur Arora
2024-09-25 23:24 ` [PATCH v8 10/11] cpuidle/poll_state: limit POLL_IDLE_RELAX_COUNT on arm64 Ankur Arora
2024-09-25 23:24 ` [PATCH v8 11/11] arm64: support cpuidle-haltpoll Ankur Arora
2024-10-02 22:42   ` Okanovic, Haris
2024-10-03  3:29     ` Ankur Arora
2024-10-16 15:13   ` Okanovic, Haris
2024-10-09  2:37 ` [PATCH v8 00/11] Enable haltpoll on arm64 zhenglifeng (A)
2024-10-15  1:53   ` Ankur Arora
2024-10-14 22:54 ` Christoph Lameter (Ampere)
2024-10-15 12:36 ` Marc Zyngier
2024-10-16 21:55   ` Ankur Arora
2024-10-17  8:19     ` Marc Zyngier
2024-10-17 18:35       ` Ankur Arora
2024-10-22 22:01         ` Ankur Arora
2024-11-05 18:30 ` Haris Okanovic
2024-11-05 18:30   ` [PATCH 1/5] asm-generic: add smp_vcond_load_relaxed() Haris Okanovic
2024-11-05 19:36     ` Christoph Lameter (Ampere)
2024-11-06 17:06       ` Okanovic, Haris
2024-11-06 11:08     ` Catalin Marinas
2024-11-06 18:13       ` Okanovic, Haris
2024-11-06 19:55         ` Catalin Marinas
2024-11-06 20:31           ` Okanovic, Haris
2024-11-06 11:39     ` Will Deacon
2024-11-06 17:18       ` Okanovic, Haris
2024-11-05 18:30   ` [PATCH 2/5] arm64: add __READ_ONCE_EX() Haris Okanovic
2024-11-05 19:39     ` Christoph Lameter (Ampere)
2024-11-06 17:37       ` Okanovic, Haris
2024-11-06 11:43     ` Will Deacon
2024-11-06 17:09       ` Okanovic, Haris
2024-11-09  9:49     ` David Laight
2024-11-05 18:30   ` [PATCH 3/5] arm64: refactor delay() to enable polling for value Haris Okanovic
2024-11-05 19:42     ` Christoph Lameter (Ampere)
2024-11-06 17:42       ` Okanovic, Haris [this message]
2024-11-06  9:18     ` Catalin Marinas
2024-11-06 17:38       ` Okanovic, Haris
2024-11-05 18:30   ` [PATCH 4/5] arm64: add smp_vcond_load_relaxed() Haris Okanovic
2024-11-05 18:30   ` [PATCH 5/5] cpuidle: implement poll_idle() using smp_vcond_load_relaxed() Haris Okanovic
2024-11-05 19:45     ` Christoph Lameter (Ampere)
2024-11-05 18:49   ` [PATCH v8 00/11] Enable haltpoll on arm64 Ankur Arora

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