Re: [PATCH] Document Linux's memory barriers [try #2]

Jesse Barnes writes:

> So ultimately mmiowb() is the only thing drivers really have to care 
> about on Altix (assuming they do DMA mapping correctly), and the rules 
> for that are fairly simple.  Then they can additionally use 
> read_relaxed() to optimize performance a bit (quite a bit on big 
> systems).

If I can be sure that all the drivers we care about on PPC use mmiowb
correctly, I can reduce or eliminate the barrier in write*, which
would be nice.

Which drivers have been audited to make sure they use mmiowb
correctly?  In particular, has the USB driver been audited?

Paul.
-
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/

---

• Follow-Ups:
  • Re: [PATCH] Document Linux's memory barriers [try #2]
    • From: Jes Sorensen <[email protected]>

• References:
  • Re: [PATCH] Document Linux's memory barriers [try #2]
    • From: Linus Torvalds <[email protected]>
  • Re: [PATCH] Document Linux's memory barriers [try #2]
    • From: Paul Mackerras <[email protected]>
  • Re: [PATCH] Document Linux's memory barriers [try #2]
    • From: Linus Torvalds <[email protected]>
  • Re: [PATCH] Document Linux's memory barriers [try #2]
    • From: Jesse Barnes <[email protected]>

• Prev by Date: RE: [future of drivers?] a proposal for binary drivers.
• Next by Date: Re: [PATCH] mm: yield during swap prefetching
• Previous by thread: Re: [PATCH] Document Linux's memory barriers [try #2]
• Next by thread: Re: [PATCH] Document Linux's memory barriers [try #2]
• 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]