I don't see any mention in the changelog of the point brought up by Ingo: http://lkml.org/lkml/2009/4/10/105 You also haven't responded to my comment about holding mmap semaphore: http://lkml.indiana.edu/hypermail/linux/kernel/0904.1/01417.html Also, please consider combining with Ingo's point with mine: the mmap semaphore will be held for the duration of that long VMA walk. Plus any userspace task can trigger that walk as often as they like via readlink. It also appears you haven't responded to Eric and Andrew's suggestion of a struct path in place of a file reference: http://lkml.indiana.edu/hypermail/linux/kernel/0904.1/01698.html Lastly, please keep me on Cc for future revisions of this patch since I am interested in following changes to the implementation of /proc/*/exe. Thanks, -Matt Helsley ----- Forwarded message from Alexey Dobriyan <adobriyan@xxxxxxxxx> ----- From: Alexey Dobriyan <adobriyan@xxxxxxxxx> To: akpm@xxxxxxxxxxxxxxxxxxxx Subject: [PATCH 14/38] Remove struct mm_struct::exe_file et al Date: Fri, 22 May 2009 08:55:08 +0400 Cc: xemul@xxxxxxxxxxxxx, containers@xxxxxxxxxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, dave@xxxxxxxxxxxxxxxxxx, mingo@xxxxxxx, torvalds@xxxxxxxxxxxxxxxxxxxx, Alexey Dobriyan <adobriyan@xxxxxxxxx> Commit 925d1c401fa6cfd0df5d2e37da8981494ccdec07 aka "procfs task exe symlink". introduced struct mm_struct::exe_file and struct mm_struct::num_exe_file_vmas. The rationale is weak: unifying MMU and no-MMU version of /proc/*/exe code. For this a) struct mm_struct becomes bigger, b) mmap/munmap/exit become slower, c) patch adds more code than removes in fact. After commit 8feae13110d60cc6287afabc2887366b0eb226c2 aka "NOMMU: Make VMAs per MM as for MMU-mode linux" no-MMU kernels also maintain list of VMAs in ->mmap, so we can switch back for MMU version of /proc/*/exe. This also helps C/R, no need to save and restore ->exe_file and to count additional references to check if there is a leak of struct file outside group of checkpointed resources. Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> --- fs/exec.c | 2 - fs/proc/base.c | 105 +++++++++++++--------------------------------- include/linux/mm.h | 12 ----- include/linux/mm_types.h | 6 --- include/linux/proc_fs.h | 20 --------- kernel/fork.c | 3 - mm/mmap.c | 22 ++-------- mm/nommu.c | 16 +------ 8 files changed, 36 insertions(+), 150 deletions(-) _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers