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Date: Fri, 27 Jul 2001 11:31:22 -0700
To: Andrea Arcangeli <andrea@suse.de>
From: Maksim Krasnyanskiy <maxk@qualcomm.com>
Subject: Re: 2.4.7 softirq incorrectness.
Cc: kuznet@ms2.inr.ac.ru, linux-kernel@vger.kernel.org
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> > Should we then create generic function (something like netif_rx_from_user) than will call do_softirq 
> > after calling netif_rx ?
>
>creating such a function is certainly ok (it must first check pending()
>before running do_softirq of course). The name shouldn't be "from user"
>because we actually call it from normal kernel context.
Sure.

> > I queue it and do tasklet_schedule(tx_task). Everything works just fine but on SMP machine I noticed that sometimes 
> > data is sent in the wrong order. And the only reason why reordering could happen is if several tx_tasks are runing at the 
>
>Do you use tasklet_enable ? 
Yep. To sync rx and tx tasks.

>This patch fixes a bug in tasklet_enable.
>(bug found by David Mosemberg) We are thinking at more CPU friendly ways
>to handle the tasklet_disable, Linus just had a suggestion, but I don't
>have time right now to think much about the alternate approches (i'm at
>ols), I will do next week. If you are usng tasklet_enable you may want
>to give it a spin.
Applied to 2.4.8-pre1. Didn't make any difference. 
Also it doesn't fix the scenario that I described (reschedule while running). I'm still wondering why don't I hit that trylock/BUG 
in tasklet_action.

Thanks
Max

Maksim Krasnyanskiy	
Senior Kernel Engineer
Qualcomm Incorporated

maxk@qualcomm.com
http://bluez.sf.net
http://vtun.sf.net

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