Hello Michal... On 2016-07-12 16:07, Michal Hocko wrote:
/proc/slabinfo could at least point on who is eating that memory.
Thanks. I have made another test (and thus again put the RAID10 out of sync for the 100th time, sigh) and made regular snapshots of slabinfo which I have attached to this mail.
Direct IO doesn't get throttled like buffered IO.
Is buffered i/o not used in both cases if I don't explicitly request
direct i/o?
dd if=/dev/zero /dev/md126p5 bs=512K
and dd if=/dev/zero /dev/mapper/test-device bs=512K
Given that the test-device is dm-crypt on md125p5. Aren't both using
buffered i/o?
the number of pages under writeback was more or less same throughout the time but there are some local fluctuations when some pages do get completed.
The pages under writeback are those directly destined for the disk, so after dm-crypt had done its encryption?
If not you can enable allocator trace point for a particular object size (or range of sizes) and see who is requesting them.
If that support is baked into the Fedora provided kernel that is. Ifyou could give me a few hints or pointers, how to properly do a allocator
trace point and get some decent data out of it, that would be nice. Thanks, Matthias -- Dipl.-Inf. (FH) Matthias Dahl | Software Engineer | binary-island.eu services: custom software [desktop, mobile, web], server administration
Attachment:
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