Messages in this thread | | | Date | Tue, 28 Feb 2012 07:41:54 +0000 | From | "Jan Beulich" <> | Subject | Re: [PATCH v2] consolidate WARN_...ONCE() static variables |
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>>> On 28.02.12 at 01:03, Andrew Morton <akpm@linux-foundation.org> wrote: > On Mon, 27 Feb 2012 15:10:34 +0000 > "Jan Beulich" <JBeulich@suse.com> wrote: > >> Due to the alignment of following variables, these typically consume >> more than just the single byte that 'bool' requires, and as there are >> a few hundred instances, the cache pollution (not so much the waste of >> memory) sums up. Put these variables into their own section, outside >> of any half way frequently used memory range. >> >> v2: Do the same also to the __warned variable of rcu_lockdep_assert(). >> (Don't, however, include the ones used by printk_once() and alike, as >> they can potentially be hot.) > > I have a bad feeling that I still don't understand this patch. Ho hum. > > What are the rules for the new .data.unlikely section? When should > people put variables into this section? Perhaps we can document this > somewhere?
If I knew the "where" part of this, I could put together a few sentences. I just grep-ed through Documentation/, without finding e.g. any rules or guidelines for using {,un}likely()...
Jan
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