Hello Justin, Thanks for the ping. On Wed, Oct 31, 2012 at 10:06 PM, Justin Lebar <justin.lebar@xxxxxxxxx> wrote: > I noticed that statm's "shared" field doesn't match the sum of all the > "shared" entries in smaps [1]. > > The kernel docs explain that statm's "shared" field is "number of > pages that are shared (i.e. backed by a file)" [2]. smaps appears to > call a page shared if it's mapped by at least two processes, which > explains this discrepancy. > > I'm not a kernel hacker, but it appears to me they do mean "i.e." and > not "e.g." in the statm description: In > fs/proc/task_mmu.c::task_statm, I see > > *shared = get_mm_counter(mm, MM_FILEPAGES); > > Here's a patch which updates the man page to match the (hopefully > correct) kernel docs. > > Subject: [PATCH] proc.5: statm's "shared" field refers to pages backed by > files. Your explanation seems reasonable to me, and matches what I can glean from the kernel source. I've applied your patch. Thanks, Michael > --- > man5/proc.5 | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/man5/proc.5 b/man5/proc.5 > index 88af7c5..855a2e0 100644 > --- a/man5/proc.5 > +++ b/man5/proc.5 > @@ -947,7 +947,7 @@ size total program size > (same as VmSize in \fI/proc/[pid]/status\fP) > resident resident set size > (same as VmRSS in \fI/proc/[pid]/status\fP) > -share shared pages (from shared mappings) > +share shared pages (i.e., backed by a file) > text text (code) > .\" (not including libs; broken, includes data segment) > lib library (unused in Linux 2.6) > -- > 1.7.10.4 > > I've also attached the patch in case gmail messes it up somehow. > > -Justin > > [1] https://bugzilla.mozilla.org/show_bug.cgi?id=807181 > [2] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=Documentation/filesystems/proc.txt;h=a1793d670cd01bd374eddf54ffdfc768504291ff;hb=HEAD -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Author of "The Linux Programming Interface"; http://man7.org/tlpi/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
