Then what is the problem?

If you Google for "Out of memory during "large" request total sbrk()" you will get your answers.

Without seeing your code, I'm using the ESP module to guess that you are trying to upload a file too big for your upload_size_limit on the server.

Down in the gloomy bowels of the underlying C, sbrk() increments the program's data space by increment bytes. See setlimit(2) in your man pages.

Caveat: This may not be very helpful in solving your problem; with a bit more information, we may be able to offer some possible workarounds.

bh_perl:

Did you review the cygwin documentation about changing the memory limit? I don't know if cygwin still works that way (as the last time I used this setting was for cygwin v1.5x and now I'm on v1.7x). Give it a try and see if that relaxes your memory limit.

I just looked around and found a direct link to the documentation in question: http://cygwin.com/faq/faq-nochunks.html#faq.programming.adjusting-heap, so it looks like it's still relevent to the current version.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

The default cygwin heap size is around 300MB so increasing that value will help. Some things I discovered with this:

(1) If you set the value too high, things can lock up for cygwin or the system. Be sure to stay below the system swap space less the memory of any running processes.

(2) cygwin perl seems to be built using the perl malloc which seems to request a pool of memory large enough for your request and then some. I've seen this result in an approximate 2X larger memory request from the system which can lead to OOM death much sooner than one might expect. At the very least, it can run out one large allocation earlier than one has requested...then boom.

Hahaha! $frobnitz - hilarious!

Out of memory during "large" request for %s

(F) The malloc() function returned 0, indicating there was insufficient remaining memory (or virtual memory) to satisfy the request. However, the request was judged large enough (compile-time default is 64K), so a possibility to shut down by trapping this error is granted.