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mmap002 execution time doubled... good or bad sign?

DISCUSSION Roger Larsson 2 participants 2 messages Feb 10, 2001 – Feb 11, 2001 Memory management

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Hi,

I have been running various stress tests on disk for some time. streaming write, copy, read, diff, dbench and mmap002

This is what I have seen:

Quoted 1 line

From 2.4.0 to 2.4.1 with Marcelos patch write were above 10 MB/s

and read >13 MB/s, dbench > 10 MB/s, mmap took around 2m30.

After 2.4.1-pre8 (did not test anything in between)
Write is at 9-10 [lost 1 MB/s] read is down to 11-12 MB/s [lost 2 MB/s] dbench > 9 MB/s [one MB/s there too]

But the really strange one - mmap002 now takes > 4m30 Is this expected / good behaviour? mmap002 abuses mmaps...

/RogerL

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#1 lore raw
Quoted 8 lines · Roger Larsson

Hi,

I have been running various stress tests on disk for some time. streaming write, copy, read, diff, dbench and mmap002

This is what I have seen:

Quoted 1 line

From 2.4.0 to 2.4.1 with Marcelos patch write were above 10 MB/s

Quoted 8 lines

and read >13 MB/s, dbench > 10 MB/s, mmap took around 2m30.

After 2.4.1-pre8 (did not test anything in between)
Write is at 9-10 [lost 1 MB/s] read is down to 11-12 MB/s [lost 2 MB/s] dbench > 9 MB/s [one MB/s there too]

But the really strange one - mmap002 now takes > 4m30 Is this expected / good behaviour? mmap002 abuses mmaps...

These are probably Jens modifications to the block queuing mechanisms since there were no VM changes from 2.4.1-pre8 to now in Linus tree.

Its not necessarily a bad thing, since Jens modifications make processes throttle on IO sooner.

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