58b94d88de
It's possible that we receive a packet that is larger than current window. If it's the first packet in this way, it will cause it to increase rwnd_over. Then, if we receive another data chunk (specially as SCTP allows you to have one data chunk in flight even during 0 window), rwnd_over will be overwritten instead of added to. In the long run, this could cause the window to grow bigger than its initial size, as rwnd_over would be charged only for the last received data chunk while the code will try open the window for all packets that were received and had its value in rwnd_over overwritten. This, then, can lead to the worsening of payload/buffer ratio and cause rwnd_press to kick in more often. The fix is to sum it too, same as is done for rwnd_press, so that if we receive 3 chunks after closing the window, we still have to release that same amount before re-opening it. Log snippet from sctp_test exhibiting the issue: [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) [ 146.209232] sctp: sctp_assoc_rwnd_decrease: association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1! [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) [ 146.209232] sctp: sctp_assoc_rwnd_decrease: association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1! [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) [ 146.209232] sctp: sctp_assoc_rwnd_decrease: association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1! [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| Documentation | ||
| arch | ||
| block | ||
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| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
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| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.