Re: [PATCH 0/11] Update version of write stream ID patchset

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



>>>>> "Andreas" == Andreas Dilger <adilger@xxxxxxxxx> writes:

Andreas> It doesn't cost anything to reserve the first 32 values for
Andreas> filesystem metadata, and they can be aggregated more or less
Andreas> depending on the hardware capabilities.  Even if current
Andreas> devices only support 4 or 8 streams, I'm sure that this will
Andreas> improve in the future, so it doesn't make sense to limit
Andreas> ourselves based on the very first devices on the market.

I am not against reserving parts of the namespace. As long as the
anticipation is that those 32 values in practice will be consolidated
into probably 2 (journal and metadata) in a static fashion.

Because, as I said, there are performance and serialization issues
wrt. closing and opening streams. So I don't think doing it in the
hotpath is going to fly.

Andreas> Also, this opens up interesting possibilities for blktrace, DM
Andreas> layers like dm-thinp, bcache, etc. that are currently lacking
Andreas> any kind of data on how they should allocate blocks.  Ted
Andreas> described the contortions he does to map from block offsets in
Andreas> blktrace to filesystem metadata using debugfs output and
Andreas> scripts, and not everyone is as knowledgeable about filesystem
Andreas> internals as he is, but still wants to be able to diagnose
Andreas> filesystem IO latency issues.

I am a big proponent of I/O tagging. We use it extensively in various
products and it works beautifully. That's why I would like to see the
storage standards being able to support it.

-- 
Martin K. Petersen	Oracle Linux Engineering
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux