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https://github.com/checkpoint-restore/criu
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Performance experiments show, that we spend (relatively) a lot of time mremap-ing areas from premap area into their proper places. This time depends on the task being restored, but for those with many vmas this can be up to 20%. The thing is that premapping is only needed to restore cow pages since we don't have any API in the kernel to share a page between two or more anonymous vmas. For non-cowing areas we map mmap() them directly in place. But for such cases we'll also need to restore the page's contents also from the pie code. Doing the whole page-read code from PIE is way too complex (for now), so the proposal is to optimize the case when we have a single local pagemap layer. This is what pr.pieok boolean stands for. v2: * Fixed ARM compiling (vma addresses formatting) * Unused tail of premapped area was left in task after restore * Preadv-ing pages in restorer context worked on corrupted iovs due to mistakes in pointer arithmetics * AIO mapping skipped at premap wasn't mapped in pie * Growsdown VMAs should sometimes (when they are "guarded" by previous VMA and guard page's contents cannot be restored in place) be premmaped * Always premmap for lazy-pages restore Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
CRIU (Checkpoint and Restore in Userspace)
An utility to checkpoint/restore tasks. Using this tool, you can freeze a running application (or part of it) and checkpoint it to a hard drive as a collection of files. You can then use the files to restore and run the application from the point it was frozen at. The distinctive feature of the CRIU project is that it is mainly implemented in user space.
The project home is at http://criu.org.
Pages worth starting with are:
- Kernel configuration, compilation, etc
- A simple example of usage
- More sophisticated example with graphical app
A video tour on basic CRIU features
How to contribute
- How to submit patches;
- Send all bug reports to mailing list;
- Spread the word about CRIU in social networks;