Messages in this thread | | | Date | Thu, 12 Mar 2015 14:24:44 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH 0/6] new zram statistics reporting scheme |
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On (03/12/15 14:11), Minchan Kim wrote: > I think we don't need CONFIG_ZRAM_OLD_STATS. > For example, for mem_used_max, we could add pr_warn_once in > *mem_used_max_show* but not *mem_used_max_store*. so, old users will see > deprecated message when they try to *read* the vaule old stat while they > will write new value. > One or two year later, we could remove mem_used_max_show then everyone > should read the vaule /sys/block/zram0/mm_stat. > > > > > > cat /sys/block/zram/mem_used_max > > > cat /sys/block/zram/mm_stat | awk friend > > > > > > How about changing only writeable, not readable for duplicated stats > > > in /sys/block/zram? So, user will have writeable stat to set some > > > options in /sys/block/zram and readable stat to get some data in > > > /sys/block/zram/[io|mm]_stat if the stat is duplicated in both. > > > > Sorry, I probably didn't drink enough coffee today, can you please > > rephrase or give a trivial example? > > Sorry, I was vague. I meant users can read the vaule for > mem_used_max and mem_limit in two places(ie, /sys/block/zram/ > and /sys/block/zram/mm_stat). If we feel it's handy for user, > i am not against that. But if there is no reason, I want to > make /sys/block/zram/ stat write-only if it is possible stat > like mem_used_max. I guess It's easier rule for user.
in a long term -- yes. duplication must go away. we provide [mm|io]_stat nodes to do stats show.
so, -- RW will be downgraded to WO -- RO will be removed
(I'm talking about those attrs that are currently visible in two places -- the original per-stat sysfs node and new [mm|io]_stat node).
and this is what CONFIG_ZRAM_OLD_STATS was doing: downgrade of RW to WO, removal of some RO attrs. but I'd prefer to go with warn once plan and do this downgrade/removal manually two years later.
-ss
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