On Tue, 2012-12-04 at 16:24 -0800, Andrew Morton wrote:

On Tue, 04 Dec 2012 18:17:08 -0600
Matt Mackall [off-list ref] wrote:

quoted

On Tue, 2012-12-04 at 15:21 -0800, Andrew Morton wrote:

quoted

On Tue, 04 Dec 2012 09:15:10 +0400
Pavel Emelyanov [off-list ref] wrote:

quoted

quoted

Two alternatives come to mind:

1)  Use /proc/pid/pagemap (Documentation/vm/pagemap.txt) in some
    fashion to determine which pages have been touched.

[momentarily coming out of kernel retirement for old man rant]

This is a popular interface anti-pattern.

You shouldn't use an interface that gives you huge amount of STATE to
detect small amounts of CHANGE via manual differentiation.

I'm not sure that's what checkpoint-restart will be doing.  If we want
to determine "which pages have been touched since the last checkpoint
ten minutes ago" then that set of touched pages *is* state.  And it's
not "small"!

Yeah, there is definitely a middle-ground here between "I want
high-frequency updates" and "I want to see the whole picture". 
The filesystem analogy is backups: we don't have any good way to say
"find me all files changed since yesterday" short of "find all files".
The closest thing is explicit snapshotting.

-- 
Mathematics is the supreme nostalgia of our time.


--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>