Messages in this thread | | | Date | Wed, 14 Jan 2015 20:07:06 +0530 | Subject | Re: [RFC][PATCH] procfs: Add /proc/<pid>/mapped_files | From | Siddhesh Poyarekar <> |
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On 14 January 2015 at 19:43, Rasmus Villemoes <linux@rasmusvillemoes.dk> wrote: > Just thinking out loud: Could one simply mark a VMA as being used for > stack during the clone call (is there room in vm_flags, or does > VM_GROWSDOWN already tell the whole story?), and then write the TID into > a new field in the VMA - I think one could make a union with vm_pgoff so > as not to enlarge the structure.
vm_flags does not have space IIRC (that was my first approach at implementing this) and VM_GROWSDOWN is not sufficient. If we can make a union with vm_pgoff like you say, we probably don't need a flag value; a non-zero value could indicate that it is a thread stack.
One problem with caching the value on clone like this though is that the stack could change due to a setcontext, but AFAICT we don't care about that for the process stack either.
Siddhesh -- http://siddhesh.in
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