On Wed, Aug 24, 2016 at 11:01 AM, Haomai Wang <haomai@xxxxxxxx> wrote: > On Wed, Aug 24, 2016 at 2:13 AM, Sage Weil <sweil@xxxxxxxxxx> wrote: >> This is huge. It takes the pg_info_t str from 306 bytes to 847 bytes, and >> this _info omap key is rewritten on *every* IO. >> >> We could shrink this down significant with varint and/or delta encoding >> since a huge portion of it is just a bunch of uint64_t counters. This >> will probably cost some CPU time, but OTOH it'll also shrink our metadata >> down a fair bit too which will pay off later. >> >> Anybody want to tackle this? > > what about separating "object_stat_collection_t stats" from pg_stat_t? > pg info should be unchanged for most of times, we could only update > object related stats. This may help to reduce half bytes. Or we only store increment values and keep the full in memory(may reduce to 20-30bytes). In period time we store the full structure(only hundreds of bytes).... > >> sage >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
