lkml.org 
[lkml]   [2010]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 03/10] Use percpu stats
    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.



    \
     
     \ /
      Last update: 2010-08-30 18:23    [W:0.022 / U:29.672 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site