Message-ID: <436EEEA4.1020703@ccoss.com.cn>
Date: Mon, 07 Nov 2005 14:05:24 +0800
From: liyu <liyu@ccoss.com.cn>
User-Agent: Mozilla Thunderbird 1.0.6 (X11/20050716)
MIME-Version: 1.0
To: LKML <linux-kernel@vger.kernel.org>
Subject: [question] I doublt on timer interrput.
Content-Type: text/plain; charset=gb18030; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 917
Lines: 35

Hi, all:

    I have one question about timer interrupt (i386 architecture).

    As we known, the timer emit HZ times interrputs per second,
and in i386. The interrupt handler will call scheduler_tick()
each time (on i386 at least, both enable or disable APIC).

    On my Celeron machine(IOW, only one CPU, not SMP/SMT), I defined
a global int variable 'tick_count' in kernel/sched.c, and add one line
of code like follow in scheduler_tick():

    ++tick_count;

    but I found it is not same with content of the /proc/interrupts,
and the differennt between them is not little.
   
    I can not understand why that is.
   
    Any useful idea.


-liyu / NOW~


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/