Then it looks like the safest solution is the use either ftruncate or
the lseek method and then touch the first byte of all memory pages.
Unfortunately, I see two problems with this. First, there is a clear
performance hit on the startup time. And second, we will have to find
a pretty smart way to do this or we will completely break the memory
affinity stuff.
george.
On Mar 30, 2009, at 13:24 , Iain Bason wrote:
On Mar 30, 2009, at 12:05 PM, Jeff Squyres wrote:
But don't we need the whole area to be zero filled?
It will be zero-filled on demand using the lseek/touch method.
However, the OS may not reserve space for the skipped pages or disk
blocks. Thus one could still get out of memory or file system full
errors at arbitrary points. Presumably one could also get segfaults
from an mmap'ed segment whose pages couldn't be allocated when the
demand came.
Iain
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