Messages in this thread | | | Date | Wed, 5 Mar 2008 14:12:29 -0800 | From | Andrew Morton <> | Subject | Re: [patch 1/3] Relay Reset Consumed |
| |
On Mon, 03 Mar 2008 15:51:50 -0800 "David J. Wilder" <dwilder@us.ibm.com> wrote:
> This patch allows relay channels to be reset i.e. unconsumed. > Basically allows a 'rewind' function for flight-recorder tracing. > > +void relay_reset_consumed(struct rchan *chan) > +{ > + unsigned int i; > + struct rchan_buf *prev = NULL; > + > + if (!chan) > + return; > + > + for (i = 0; i < NR_CPUS; i++) {
Use of NR_CPUS is usually wrong. In this case it seems you should be using for_each_possible_cpu().
Also the existing usage of NR_CPUS in relay_subbufs_consumed() should be switched to using cpu_possible().
New usage of NR_CPUS might be checkpatch-worthy, actually:
akpm:/usr/src/25> grep -l '^+.*NR_CPUS' patches/*.patch patches/ext4-mm-mballoc-core.patch patches/git-kvm.patch patches/git-perfmon.patch patches/relay-reset-consumed.patch patches/x86-andi-git-x86.patch patches/x86-andi-smp-switch-optimize.patch
that's a sample of 1852 patches.
An appropriate warning would be "Usage of NR_CPUS is often wrong - should you be using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc?".
| |