Re: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush()

Rusty Russell wrote:

On Tue, 2006-11-07 at 16:22 -0800, Jeremy Fitzhardinge wrote:

kunmap_atomic() will call kpte_clear_flush with vaddr/ptep arguments
which don't correspond if the vaddr is just a normal lowmem address
(ie, not in the KMAP area).  This patch makes sure that the pte is
only cleared if kmap area was actually used for the mapping.

Or in other words, if kmap_atomic() does nothing, kunmap_atomic() should
do nothing.

Sure. I guess there's no particular reason why kmap_atomic() couldn't always map, but I guess avoid the pagetable updates is worthwhile.

   J
-
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] Fix kunmap_atomic's use of kpte_clear_flush()
    • From: Jeremy Fitzhardinge <[email protected]>
  • Re: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush()
    • From: Rusty Russell <[email protected]>

• Prev by Date: Re: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush()
• Next by Date: Re: Mapping between ata9 and /dev/sd[a-z]
• Previous by thread: Re: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush()
• Next by thread: Re: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush()
• 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]