Date: Fri, 25 Jul 2003 06:08:08 +0800 From: "David Xu" <davidxu@freebsd.org> To: "Julian Elischer" <julian@elischer.org>, <deischen@freebsd.org> Cc: marcel@xcllnt.net Subject: Re: KSD/TSD take 2 (was: KSE critical regions) Message-ID: <002501c35230$1205be60$0701a8c0@tiger> References: <Pine.BSF.4.21.0307241229170.69488-100000@InterJet.elischer.org>
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----- Original Message -----=20
From: "Julian Elischer" <julian@elischer.org>
To: <deischen@freebsd.org>
Cc: <threads@freebsd.org>; "David Xu" <davidxu@freebsd.org>; =
<marcel@xcllnt.net>
Sent: Friday, July 25, 2003 4:59 AM
Subject: Re: KSD/TSD take 2 (was: KSE critical regions)
to the kernel.
>=20
> In the i386 case, (and only the i386 case (unless the amd-64 case is =
the
> same)) the KSE MAILBOX is what we are pointing %gs:0 at, and in that
> case, the pointer to the TCB (not the thread mailbox) is stored there.
> (and set there by the UTS when scheduling a thread).
>=20
> Thus the struct kse_mailbox would have:
>=20
> struct kse_mailbox {=20
> #ifdef __i386__
> void *TLS_tcb; /* current TCB for TLS =
*/
> #endif
> uint32_t km_version; /* Mailbox version */
> uint32_t km_flags; /* KSE flags */
> struct kse_thr_mailbox *km_curthread; /* Currently running =
thread */
> struct kse_thr_mailbox *km_completed; /* Threads back from =
kernel */
> [...]
>=20
userland can always adapt the layout by:
struct lib_kse_mailbox {
void *TLS_tcb;
struct kse_mailbox kmbx;
};
and set base address to lib_kse_mailbox, userland can
do whatever it wants to do. same thing can be done for
thread mailbox.
I don't think too many fields not related to interaction
between kernel and userland should be pushed into mailbox,
it is too ugly.
David Xu
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