From: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
To: "the arch/x86 maintainers" <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Hungry for hardware timers
Date: Tue, 7 Sep 2010 12:02:04 +0530 [thread overview]
Message-ID: <AANLkTiktFQWvz-TzewKYEd1wtEbe3cVFjFca4dFtUTCV@mail.gmail.com> (raw)
Hello,
I am investigating how many hardware timers are available for kernel,
system applications and user applications for x86 platforms.
Is there any help available for it so that systems developers can use
a hook up an interrupt and use any hardware timer.
In APIC timer, but each core is having only one timer and it is
already utilized by Linux :
... APIC TMICT: 00002078
... APIC TMCCT: 00000b5f
... APIC TDCR: 00000003
HPET have 3 timers :
[ 0.328157] hpet: ID: 0x8086a201, PERIOD: 0x429b17f
[ 0.328315] hpet: CFG: 0x3, STATUS: 0x0
[ 0.328472] hpet: COUNTER_l: 0x6ff120, COUNTER_h: 0x0
[ 0.329006] hpet: T0: CFG_l: 0x138, CFG_h: 0xf00000
[ 0.329165] hpet: T0: CMP_l: 0x701baa, CMP_h: 0x0
[ 0.329324] hpet: T0 ROUTE_l: 0x0, ROUTE_h: 0x0
[ 0.329483] hpet: T1: CFG_l: 0x0, CFG_h: 0xf00000
[ 0.330006] hpet: T1: CMP_l: 0xffffffff, CMP_h: 0x0
[ 0.330166] hpet: T1 ROUTE_l: 0x0, ROUTE_h: 0x0
[ 0.331005] hpet: T2: CFG_l: 0x0, CFG_h: 0xf00800
[ 0.331168] hpet: T2: CMP_l: 0xdf751c, CMP_h: 0x0
[ 0.331328] hpet: T2 ROUTE_l: 0x0, ROUTE_h: 0x0
T0 and T2 is already used by Linux and T1 is used for RTC
System 8254 timer have 3 timers but it seems it is also used by Linux :
[ 4923.510233] 0: 83ae 1: 1102 2: 37f2
[ 4923.510251] 0: 8382 1: d10 2: 37dc
So I am curious why Linux kernel is consuming so many timers. And how
can I get spare hardware timers.
Thanks,
--
Jaswinder Singh.
next reply other threads:[~2010-09-07 6:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-07 6:32 Jaswinder Singh Rajput [this message]
2010-09-07 7:59 ` Hungry for hardware timers Clemens Ladisch
2010-09-07 8:23 ` Jaswinder Singh Rajput
2010-09-07 9:05 ` Clemens Ladisch
2010-09-07 9:57 ` Jaswinder Singh Rajput
2010-09-07 10:55 ` Clemens Ladisch
2010-09-17 5:48 ` Jaswinder Singh Rajput
2010-09-17 7:38 ` Clemens Ladisch
2010-12-10 4:47 ` Jaswinder Singh
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