Re: [Xen-devel] nptl status? - Ian Pratt - com.xensource.lists.xen-devel

2 messages in com.xensource.lists.xen-develRe: [Xen-devel] nptl status?

From	Sent On	Attachments
Stuart Jansen	29 Nov 2004 18:13
Ian Pratt	29 Nov 2004 18:23

Subject:	Re: [Xen-devel] nptl status?
From:	Ian Pratt (Ian....@cl.cam.ac.uk)
Date:	11/29/2004 06:23:36 PM
List:	com.xensource.lists.xen-devel

I read, I think on the Xen Web site, that Xen doesn't support NPTL yet. Digging through the Xen mailing list a few days ago, I saw a message that implied it is working now. What is the current status of NPTL in Xen? Out of curiosity, if it is not yet supported, what would be needed to support it? How hard would it be for a person with zero Xen experience to ramp up and work on adding NPTL support?

NPTL is supported, but we're forced to take traps for almost every attempt to access thread local storage, which is slow (I think Rik said 12-15% on a kernel compile).

The only way to improve on this would be to have our own very slightly modified version of libc that could be installed to restore full performance. We're hoping to look into this at some point.

Disabling NPTL works for most people.

Ian