On Wed, 22 Aug 2007 14:15:16 -0500 Dean Nelson <[EMAIL PROTECTED]> wrote:
> On Wed, Aug 22, 2007 at 11:04:22AM -0700, Andrew Morton wrote: > > On Wed, 22 Aug 2007 12:00:11 -0500 > > Dean Nelson <[EMAIL PROTECTED]> wrote: > > > > > > > > 3) WARNING: declaring multiple variables together should be avoided > > > > > > checkpatch.pl is erroneously commplaining about the following found in > > > five > > > different functions in arch/ia64/sn/kernel/xpmem_pfn.c. > > > > > > int n_pgs = xpmem_num_of_pages(vaddr, size); > > > > What warning does it generate here? > > The WARNING #3 above "declaring multiple variables together should be > avoided". > There is only one variable being declared, which happens to be initialized by > the function xpmem_num_of_pages(). Ah, I think I recall seeing a report of that earlier. Maybe it's been fixed? > ... > > > I've switched from using nopage to using fault. I read that it is intended > > > that nopfn also goes away. If this is the case, then the BUG_ON if > > > VM_PFNMAP > > > is set would make __do_fault() a rather unfriendly replacement for > > > do_no_pfn(). > > > > > > > - xpmem_attach() does smp_processor_id() in preemptible code. Lucky > > > > that > > > > ia64 doesn't do preempt? > > > > > > Actually, the code is fine as is even with preemption configured on. All > > > it's > > > doing is ensuring that the thread was previously pinned to the CPU it's > > > currently running on. If it is, it can't be moved to another CPU via > > > preemption, and if it isn't, the check will fail and we'll return -EINVAL > > > and all is well. > > > > OK. Running smp_processor_id() from within preemptible code will generate > > a warning, but the code is sneaky enough to prevent that warning if the > > calling task happens to be pinned to a single CPU. > > Would it make more sense in this particular case to replace the call to > smp_processor_id() in xpmem_attach() with a call to raw_smp_processor_id() > instead, and add a comment explaining why? Your call ;) Either will be OK, I expect. - 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/
