[lkml]   [2004]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Subjectget_user_pages question
I have been tryin to use get_user_pages() on malloced memory and get the
list of pages but it does not work as
I expected:
1. malloc a buffer in user space
2. issue ioctl, invoke get_user_pages() and save the page descriptors I
3. at a later time, issue another ioctl, invoke get_user_pages() again
and save another copy of the page descriptors.
4. Compare the two lists of page descriptors. They're not all the same.

Apparently some pages were discarded and the subsequent page fault
brought a new page. I expected the original page to be in the swap cache
and get the old page again. I repeated the experiment but before the
first ioctl I wrote something to all the pages but got the same results.
I used 2.4.21-4 (RH AS 3.0).

Can anyone clarify?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 14:02    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean