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Diffstat (limited to 'README.md')
| -rw-r--r-- | README.md | 17 |
1 files changed, 16 insertions, 1 deletions
@@ -93,7 +93,22 @@ running the tests): ### Things to design -* Cache architecture +* Cache architecture : + - A RAM file is basically a bunch of pages that contain the data (rather than a segment of + malloc()'ed memory) + - A framebuffer device is basically a bunch of pages at a fixed hardware location, that cannot + grow + - In the two previous cases, the pages are never freed : they are not a cache, they are the + data itself. + - In the case of an on-disk file, the pages are a copy of the file's data that is originally + on-disk, and we might want to free these pages even while a process is using them, because + we can always reload them from the disk. + - An on-disk file with a page cache must be aware of all the places where the page is mapped, + so that it can unmap it when reclaiming pages. + - Simpler model : cached pages cannot be freed while the file is open with `FM_MMAP` +* Reclaiming physical memory : + - Freeing some cached stuff, ie swapping pages from mmap regions + - Swapping pages from processes non-mmap regions (ie real data regions) * IPC * How does a process exit, what does it do, how do processes synchronize ? * Have several threads in a single process |