I have a problem about changing a bundle, help!

I have a problem about changing a bundle, help!

[Lai Jiangshan]

Hello!
	
	Are the following statements safe? Is there any coherence problem?
And why?

	/* change the instruction */
	memcpy(ins_addr, ins_buf, sizeof(struct ia64_bundle));
 	flush_icache_range(ins_addr, ins_addr + sizeof(struct ia64_bundle));

	I have make sure that just one thread changes the instruction(bundle),
but maybe a lot of threads execute the instruction in the same time.

	Is any thread executes an error instruction(maybe an error bundle
combined with old bundle and new bundle, or other) in some condition?

	If the statements are unsafe, how can i change a bundle safely?

Best Regards!
Lai Jiangshan

RE: I have a problem about changing a bundle, help!

[Luck, Tony]

>	If the statements are unsafe, how can i change a bundle safely?

If you are on a cpu that supports "st16" (Montecito or later) then you can
use that to update the whole bundle in a single atomic write rather than
using memcpy().

Without st16, I think the only safe way to update the bundle is to ensure
that no processor is executing it while the update is occuring.

-Tony