John B Moore wrote: > After more detail examination of this problem, what I see is that the > storage for the shared memory appears to be allocated via RAMFS in the > pagecache in tiny-shmem.c (i.e. a non-mmu platform) and the storage is > mmapped when the shmat is performed. When the pagecache hits its > threshold of low RAM and starts to cleanup, the mmapped storage for > the shared memory segment gets cleaned up as well old file cache > entries. Eventually this storage gets re-used as pagecache and makes > it appear as though the JFFS2 file system has overwritten the shared > memory block when in reality the storage was freed and re-used. From > looking at the code, either the page is not getting properly flagged > as being mmapped on shmat or I am missing something in the pagecache > cleanup code since it appears that any mmapped storage in the > pagecache will always be ignored during cleanup.
If that's what's happening it'd be quite a serious bug, although SYSV SHM isn't used much on NOMMU so it could have been missed. Do you know if it does the same thing when using POSIX shared memory (if that even works)? -- Jamie _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
