On Tue, Aug 14, 2007 at 04:52:04PM +0800, Fengguang Wu wrote: > Hello, > > Matt Mackall brings us many memory-footprint-optimization > opportunities with his pagemap/kpagemap patches. However I wonder if > the binary interface can be improved. > > This seq_file based implementation iterates in the unit of vmas. So > super large vmas can be a problem. The next step is to to do address > based iteration. That should not be hard. > > Andrew, please stop me early if it is at all a wrong interface :) > > Thank you, > Fengguang > === > > Show a process's memory maps page-by-page in /proc/<pid>/pmaps. > It helps to analyze application's memory footprint 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 > > Here is a sample output: > > # cat /proc/$$/pmaps > 08048000-080c9000 r-xp 08048000 00:00 0 > 32840 129 Y_A_P__ 1 > 080c9000-080f6000 rwxp 080c9000 00:00 0 > [heap] > 32969 45 Y_A_P__ 1 > f7dba000-f7dc3000 r-xp 00000000 03:00 176633 > /lib/libnss_files-2.3.6.so > 0 1 Y_AU___ 1 > 1 1 YR_U___ 1 > 5 1 YR_U___ 1 > 8 1 Y_AU___ 1 > f7dc3000-f7dc5000 rwxp 00008000 03:00 176633 > /lib/libnss_files-2.3.6.so > 8 2 Y_A_P__ 1 > f7dc5000-f7dcd000 r-xp 00000000 03:00 176635 > /lib/libnss_nis-2.3.6.so > 0 1 Y_AU___ 1 > 1 1 YR_U___ 1 > 4 1 YR_U___ 1 > 7 1 Y_AU___ 1 > f7dcd000-f7dcf000 rwxp 00007000 03:00 176635 > /lib/libnss_nis-2.3.6.so > 7 2 Y_A_P__ 1 > f7dcf000-f7de1000 r-xp 00000000 03:00 176630 > /lib/libnsl-2.3.6.so > 0 1 Y_AU___ 1 > 1 3 YR_U___ 1 > 16 1 YR_U___ 1 > f7de1000-f7de3000 rwxp 00011000 03:00 176630 > /lib/libnsl-2.3.6.so > 17 2 Y_A_P__ 1 > [...]
That's a _lot_ of data to generate and parse. I doubt we can watch a larger app in realtime with this interface. And it doesn't give us physical page numbers either. -- Mathematics is the supreme nostalgia of our time. - 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/
