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Old 06-18-2015, 03:56 AM   #80
frostschutz
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Quote:
Originally Posted by davidfor View Post
Will strace pick up the actual IO when this is done?
Don't think so. I could do a block dump but it will only catch the first read, not subsequent re-reads from cache.

Quote:
Originally Posted by davidfor View Post
Ouch, all those file opens and rereads of the same part.
Well, that's handled by the Linux VFS cache. So it's more like a memory copy than a physical read. But it raises questions regarding how the data is processed behind the scenes. Reading 16KB of already cached data might not take particularly long. But re-parsing and re-validating of the same data might add up.
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