From mboxrd@z Thu Jan  1 00:00:00 1970
From: Maximiliano Curia <maxy@rivero.com.ar>
Subject: Dosemu and clipper applications eating all CPU
Date: Mon, 08 Mar 2004 13:11:42 -0300
Sender: linux-msdos-owner@vger.kernel.org
Message-ID: <1078762302.15406.90.camel@peperina>
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To: linux-msdos@vger.kernel.org

Hi!

I'm trying to run a clipper program inside dosemu.  It runs ok, but it
eats all the CPU cycles when it's idle. 

I've already tried changing the hogthreshold value, with no changes in
the result.

This is a snip of the strace of the process:

--- SIGALRM (Alarm clock) @ 0 (0) ---
<... vm86 resumed> )                    = -1 ENOSYS (Function not
implemented)
ioctl(4, FIONREAD, [0])                 = 0
select(7, [], NULL, NULL, {0, 0})       = 0 (Timeout)
select(7, [6], NULL, NULL, {0, 0})      = 0 (Timeout)
vm86(0x1, 0x81a2980, 0xa6, 0xfff8eff1, 0x8) = -1 ENOSYS (Function not
implemented)
vm86(0x1, 0x81a2980, 0xa6, 0xfff8eff1, 0xbffffa34) = -1 ENOSYS (Function
not implemented)
vm86(0x1, 0x81a2980, 0xa6, 0xfff8eff1, 0xbffffa34) = -1 ENOSYS (Function
not implemented)
--- SIGALRM (Alarm clock) @ 0 (0) ---
sigreturn()                             = ? (mask now [RTMIN])
ioctl(4, FIONREAD, [0])                 = 0
select(7, [], NULL, NULL, {0, 0})       = 0 (Timeout)
select(7, [6], NULL, NULL, {0, 0})      = 0 (Timeout)
vm86(0x1, 0x81a2980, 0xa6, 0xfff8eff1, 0xbffffa34 <unfinished ...>
--- SIGALRM (Alarm clock) @ 0 (0) ---
<... vm86 resumed> )                    = -1 ENOSYS (Function not
implemented)
ioctl(4, FIONREAD, [0])                 = 0
select(7, [], NULL, NULL, {0, 0})       = 0 (Timeout)
select(7, [6], NULL, NULL, {0, 0})      = 0 (Timeout)
vm86(0x1, 0x81a2980, 0xa6, 0xfff8eff1, 0xbffffa34 <unfinished ...>
--- SIGALRM (Alarm clock) @ 0 (0) ---

And it goes on like that.  While the user is doing nothing, this alarms
repeat themselves many times per second, turning the rest of the machine
into an unusable state.

When idle at the command prompt, the behaviour is notably different:

--- SIGALRM (Alarm clock) @ 0 (0) ---
sigreturn()                             = ? (mask now [])
ioctl(4, FIONREAD, [0])                 = 0
gettimeofday({1078759812, 698914}, NULL) = 0
select(8, [], NULL, NULL, {0, 0})       = 0 (Timeout)
select(8, [7], NULL, NULL, {0, 0})      = 0 (Timeout)
gettimeofday({1078759812, 699517}, NULL) = 0
vm86(0x1, 0x81778a0, 0xa6, 0xfff8dff1, 0) = -1 ENOSYS (Function not
implemented)
vm86(0x1, 0x81778a0, 0xa6, 0xfff8dff1, 0) = -1 ENOSYS (Function not
implemented)
gettimeofday({1078759812, 700033}, NULL) = 0
vm86(0x1, 0x81778a0, 0xa6, 0xfff8dff1, 0) = -1 ENOSYS (Function not
implemented)
vm86(0x1, 0x81778a0, 0xa6, 0xfff8dff1, 0) = -1 ENOSYS (Function not
implemented)
(...) repeating gettimeofday+vm86+vm86 6 more times (...)
gettimeofday({1078759812, 703178}, NULL) = 0
vm86(0x1, 0x81778a0, 0xa6, 0xfff8dff1, 0) = -1 ENOSYS (Function not
implemented)
nanosleep({0, 80000000}, 0)             = ? ERESTART_RESTARTBLOCK (To be
restarted)
--- SIGALRM (Alarm clock) @ 0 (0) ---

I've been told this is a known problem, but I'm hoping it can be fixed
in some way.

-- 
Saludos
/\/\ /\ >< `/