 Home |
Products |
Support |
Community |
News |
xen-devel
[Xen-devel] Xen scheduling bug?
| To: | "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx> |
|---|---|
| Subject: | [Xen-devel] Xen scheduling bug? |
| From: | "Stephen C. Tweedie" <sct@xxxxxxxxxx> |
| Date: | Sat, 15 Jul 2006 16:38:04 +0100 |
| Delivery-date: | Sat, 15 Jul 2006 08:38:33 -0700 |
| Envelope-to: | www-data@xxxxxxxxxxxxxxxxxx |
| List-help: | <mailto:xen-devel-request@lists.xensource.com?subject=help> |
| List-id: | Xen developer discussion <xen-devel.lists.xensource.com> |
| List-post: | <mailto:xen-devel@lists.xensource.com> |
| List-subscribe: | <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe> |
| List-unsubscribe: | <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe> |
| Sender: | xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
Hi all,
The arch/x86_64/kernel/entry-xen.S linux-2.6-xen.hg contains:
sysret_careful:
CFI_RESTORE_STATE
bt $TIF_NEED_RESCHED,%edx
jnc sysret_signal
XEN_BLOCK_EVENTS(%rsi) <<<<<<<<<<<<<<
pushq %rdi
CFI_ADJUST_CFA_OFFSET 8
call schedule
popq %rdi
CFI_ADJUST_CFA_OFFSET -8
jmp sysret_check
sret_careful:
The equivalent non-Xen chunk is:
sysret_careful:
CFI_RESTORE_STATE
bt $TIF_NEED_RESCHED,%edx
jnc sysret_signal
TRACE_IRQS_ON
sti <<<<<<<<<<<<<<
pushq %rdi
CFI_ADJUST_CFA_OFFSET 8
call schedule
popq %rdi
CFI_ADJUST_CFA_OFFSET -8
jmp sysret_check
Note the marked lines --- Xen is turning irqs _off_ at this point, when
non-Xen is turning them on. I just noticed it when merging the
irqtracing code.
Bug?
--Stephen
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
| <Prev in Thread] | Current Thread | [Next in Thread> |
|---|---|---|
| ||
| Previous by Date: | ROLAND Z.BERSSON, ROLAND Z.BERSSON |
|---|---|
| Next by Date: | Re: [Xen-users] usb-patch, Nivedita Singhvi |
| Previous by Thread: | [Xen-devel] Using LinuxBIOS as virtual firmware, Lu, Yinghai |
| Next by Thread: | Re: [Xen-devel] Xen scheduling bug?, Keir Fraser |
| Indexes: | [Date] [Thread] [Top] [All Lists] |
