Re: [PATCH] get_user_pages(..., write==1, ...) may return with readable pte.

On Sat, Oct 14, 2006 at 05:15:07AM -0500, Robin Holt wrote:
> > dup_mmap holds mmap_sem for write. get_user_pages caller must hold it
> > for read.
> 
> I could have sworn I checked for that and found a down_read(), but
> now that I look when I have some time, it is clearly a down_write().
> Sorry for the distraction.

I'm one to do the same thing, don't worry ;)

> It is a user job that is passing data between hosts.  The host is
> under heavy memory pressure and one rank of the MPI job gets silent
> data corruption.

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=016eb4a0ed06a3677d67a584da901f0e9a63c666

It could be this? inode reclaim calls invalidate_inode_pages, so this
one is a memory corrupter under heavy reclaim pressure.


> 
> Thanks and sorry for wasting your time,

Not at all, my pleasure.
-
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/

---

• References:
  • [PATCH] get_user_pages(..., write==1, ...) may return with readable pte.
    • From: Robin Holt <[email protected]>
  • Re: [PATCH] get_user_pages(..., write==1, ...) may return with readable pte.
    • From: Nick Piggin <[email protected]>
  • Re: [PATCH] get_user_pages(..., write==1, ...) may return with readable pte.
    • From: Robin Holt <[email protected]>

• Prev by Date: Re: [patch 3/3] mm: fault handler to replace nopage and populate
• Next by Date: undefined reference to highest_possible_node_id
• Previous by thread: Re: [PATCH] get_user_pages(..., write==1, ...) may return with readable pte.
• Next by thread: [PATCH 1/7] Char: stallion, use pr_debug macro
• Index(es):
  • Date
  • Thread

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]