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59677d3c0e
First, a file is mmap(2)ed and then mlock(2)ed. Later, it is truncated. Under "normal" circumstances, i.e., when the file is not mlock(2)ed, the pages beyond the EOF are unmapped and freed. However, when the file is mlock(2)ed, the pages beyond the EOF are unmapped but not freed because they have a non-zero wire count. This can be a mistake. Specifically, it is a mistake if the sole reason why the pages are wired is because of wired, managed mappings. Previously, unmapping the pages destroys these wired, managed mappings, but does not reduce the pages' wire count. Consequently, when the file is unmapped, the pages are not unwired because the wired mapping has been destroyed. Moreover, when the vm object is finally destroyed, the pages are leaked because they are still wired. The fix is to reduce the pages' wired count by the number of wired, managed mappings destroyed. To do this, I introduce a new pmap function pmap_page_wired_mappings() that returns the number of managed mappings to the given physical page that are wired, and I use this function in vm_object_page_remove(). Reviewed by: tegge MFC after: 6 weeks |
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| .. | ||
| clock.c | ||
| copyinout.c | ||
| interrupt.c | ||
| locore.S | ||
| machdep.c | ||
| mmu_oea.c | ||
| nexus.c | ||
| ofw_machdep.c | ||
| ofwmagic.S | ||
| swtch.S | ||
| trap_subr.S | ||
| trap.c | ||
| uio_machdep.c | ||
| uma_machdep.c | ||
| vm_machdep.c | ||