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[lwip-devel] [patch #7088] Support for mem_realloc moving memory
From: |
Simon Goldschmidt |
Subject: |
[lwip-devel] [patch #7088] Support for mem_realloc moving memory |
Date: |
Thu, 18 Feb 2010 06:34:23 +0000 |
User-agent: |
Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.2) Gecko/20100115 Firefox/3.6 |
Follow-up Comment #6, patch #7088 (project lwip):
Sorry for not being too clear. Let me first how I see this:
- we agreed that for incoming packets, it wouldn't change anything
- mem_realloc is used from pbuf_realloc only
- pbuf_realloc is currently used only for packets that are about to be sent
-> if we save memory, then only for a short time, and often far less than the
MTU
Now at the time pbuf_realloc is called, the pbuf is already filled with the
data to be sent but is too long. Instead of merely adjusting it len (and
tot_len), we call pbuf_realloc to give the unused memory back to the heap.
If mem_realloc actually moves the pbuf in memory, it will have to move the
contained data, too. And this will be done using something like memcpy.
This is why I said we trade memory-saving for memcpy: We *have* to copy data
if the new (smaller) region resides at another place in memory than the old
region.
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- [lwip-devel] [patch #7088] DNS with custom malloc/realloc contains a double free in RAM pbuf realloc, Ken Smith, 2010/02/09
- [lwip-devel] [patch #7088] DNS with custom malloc/realloc contains a double free in RAM pbuf realloc, Kieran Mansley, 2010/02/11
- [lwip-devel] [patch #7088] DNS with custom malloc/realloc contains a double free in RAM pbuf realloc, Simon Goldschmidt, 2010/02/11
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Simon Goldschmidt, 2010/02/12
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Simon Goldschmidt, 2010/02/17
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Ken Smith, 2010/02/17
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory,
Simon Goldschmidt <=
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Kieran Mansley, 2010/02/18
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Ken Smith, 2010/02/18
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Kieran Mansley, 2010/02/18
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Ken Smith, 2010/02/18
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Kieran Mansley, 2010/02/18
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Ken Smith, 2010/02/18
- [lwip-devel] [patch #7088] Support for mem_realloc moving memory, Simon Goldschmidt, 2010/02/19