Messages in this thread | | | Date | Thu, 29 Jun 2017 18:17:13 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH v1 0/7] writeback incompressible pages to storage |
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Hello,
On (06/29/17 17:47), Minchan Kim wrote: [..] > > > This patch supports writeback feature of zram so admin can set up > > > a block device and with it, zram can save the memory via writing > > > out the incompressile pages once it found it's incompressible pages > > > (1/4 comp ratio) instead of keeping the page in memory. > > > > hm, alternative idea. just an idea. can we try compressing the page > > with another algorithm? example: downcast from lz4 to zlib? we can > > set up a fallback "worst case" algorithm, so each entry can contain > > additional flag that would tell if the src page was compressed with > > the fast or slow algorithm. that sounds to me easier than "create a > > new block device and bond it to zram, etc". but I may be wrong. > > We tried it although it was static not dynamic adatation you suggested.
could you please explain more? I'm not sure I understand what was the configuration (what is static adaptation?).
> However problem was media-stream data so zlib, lzam added just pointless > overhead.
would that overhead be bigger than a full-blown I/O request to another block device (potentially slow, or under load, etc. etc.)?
-ss
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