| Date | Mon, 30 Aug 2010 11:20:10 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: [PATCH 03/10] Use percpu stats |
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On Mon, 9 Aug 2010, Nitin Gupta wrote:
> -static void zram_stat_inc(u32 *v) > +static void zram_add_stat(struct zram *zram, > + enum zram_stats_index idx, s64 val) > { > - *v = *v + 1; > + struct zram_stats_cpu *stats; > + > + preempt_disable(); > + stats = __this_cpu_ptr(zram->stats); > + u64_stats_update_begin(&stats->syncp); > + stats->count[idx] += val; > + u64_stats_update_end(&stats->syncp); > + preempt_enable();
Maybe do
#define zram_add_stat(zram, index, val) this_cpu_add(zram->stats->count[index], val)
instead? It creates an add in a single "atomic" per cpu instruction and deals with the fallback scenarios for processors that cannot handle 64 bit adds.
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