Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 19 Jan 2000 22:29:01 -0800
From:      Jason Evans <jasone@canonware.com>
To:        Matthew Dillon <dillon@apollo.backplane.com>
Cc:        Alfred Perlstein <bright@wintelcom.net>, cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG
Subject:   Re: cvs commit: src/sys/kern vfs_aio.c
Message-ID:  <20000119222901.V27689@sturm.canonware.com>
In-Reply-To: <200001200626.WAA42307@apollo.backplane.com>; from dillon@apollo.backplane.com on Wed, Jan 19, 2000 at 10:26:27PM -0800
References:  <200001200200.SAA61880@freefall.freebsd.org> <20000119210539.F20191@fw.wintelcom.net> <200001200626.WAA42307@apollo.backplane.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Jan 19, 2000 at 10:26:27PM -0800, Matthew Dillon wrote:
> :* Jason Evans <jasone@FreeBSD.org> [000119 18:23] wrote:
> :> jasone      2000/01/19 18:00:00 PST
> :> 
> :>   Modified files:
> :>     sys/kern             vfs_aio.c 
> :>   Log:
> :>   Don't tsleep() while at splbio().
> :
> :Unless it fixes some other bug, sleeping with spl raised is perfectly valid.
> 
>     Not only that, but this change *introduces* a race condition.  The
>     splx(s) CANNOT occur before the tsleep() or you have a race between
>     setting the KAIO_WAKEUP flag and an interrupt occuring just prior
>     to the tsleep().
> 
>     Jason, please revert this change.  tsleep()ing with the spl raised
>     is used all over the kernel for the precise reason that it was used 
>     here:  To prevent an interrupt/wakeup/tsleep race from occuring.

Okay, will do.

Thanks,
Jason


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000119222901.V27689>