On Thu, Aug 16, 2007 at 09:38:46PM -0500, Matt Mackall wrote: > On Fri, Aug 17, 2007 at 06:05:20AM +0800, Fengguang Wu wrote: > > Show a process's page-by-page address space infomation in /proc/<pid>/pmaps. > > It helps to analyze applications' memory footprints in a comprehensive way. > > > > Pages share the same states are grouped into a page range. > > For each page range, the following fields are exported: > > - first page index > > - number of pages in the range > > - well known page/pte flags > > - number of mmap users > > > > Only page flags not expected to disappear in the near future are exported: > > > > Y:young R:referenced A:active U:uptodate P:ptedirty D:dirty W:writeback > ... > > > The concern of dataset size is taken care of by working in a sparse way: > > > > 1) It will only generate output for resident pages, that normally is > > much smaller than the mapped size. Take my shell for example, the > > (size:rss) ratio is (7:1)! > > > > wfg ~% cat /proc/$$/smaps |grep Size|sum > > sum 50552.000 > > avg 777.723 > > > > wfg ~% cat /proc/$$/smaps |grep Rss|sum > > sum 7604.000 > > avg 116.985 > > > > 2) The page range trick suppresses more output. > > > > It's interesting to see that the seq_file interface demands some > > more programming efforts, and provides such flexibility as well. > > I'm so-so on this.
Not that way! It's a good thing that people have different experiences and hence viewpoints. Maybe the concept of PFN sharing are straightforward to you, while I have been playing with seq_file a lot. > On the downside: > > - requires lots of parsing > - isn't random-access > - probably significantly slower than pagemap That could be true. Maybe some user with huge datasets will give us some idea about the performance. I don't know, maybe it's application dependent. Anyway I don't think it's fair to merge a binary interface without the challenge from a textual one ;) Thank you, Fengguang - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
