Before 3.5 cgrups stats files shown only devices with activity. But latest kernel shows stats for all devices. The previous implementation looks better. Imagine a server machine with hundreds cgroups and hundreds iSCSI block devices (where cgroup uses just a few block devices). This generates *a lot* of useless data that requires more resources to process/store. Recover previous behaviour by skipping entries with zero stats. Signed-off-by: Anatol Pomozov <anatol.pomozov@xxxxxxxxx> --- block/blk-cgroup.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index e8918ff..915c2b0 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -548,6 +548,9 @@ u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v) if (!dname) return 0; + if (!v) + return 0; + seq_printf(sf, "%s %llu\n", dname, (unsigned long long)v); return v; } @@ -571,19 +574,23 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, [BLKG_RWSTAT_ASYNC] = "Async", }; const char *dname = blkg_dev_name(pd->blkg); - u64 v; + u64 total; int i; if (!dname) return 0; + total = rwstat->cnt[BLKG_RWSTAT_READ] + rwstat->cnt[BLKG_RWSTAT_WRITE]; + /* skip devices with no activity */ + if (!total) + return 0; + for (i = 0; i < BLKG_RWSTAT_NR; i++) seq_printf(sf, "%s %s %llu\n", dname, rwstr[i], (unsigned long long)rwstat->cnt[i]); - v = rwstat->cnt[BLKG_RWSTAT_READ] + rwstat->cnt[BLKG_RWSTAT_WRITE]; - seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v); - return v; + seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)total); + return total; } EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat); -- 1.8.3 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
