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| /freebsd/sys/i386/i386/ |
| H A D | vm_machdep.c | diff 4c0e268adf5c81b1daa772bdd614385c3bca531a Wed Oct 12 03:41:48 CEST 2005 Stephan Uphoff <ups@FreeBSD.org> Ensure that a thread stays on same CPU when calculating per CPU
TLB shootdown requirements. Otherwise a CPU may not get the needed
TLB invalidation.
The PTE valid and access flags can not be used here to avoid TLB
shootdowns unless sf->cpumask == all_cpus.
( Otherwise some CPUs may still hold an even older entry in the TLB)
Since sf_buf_alloc mappings are normally always used this is
also not really useful and presetting accessed and modified
allows the CPU to speculatively load the entry into the TLB.
Both bugs can cause random data corruption.
MFC after: 3 days
diff 4c0e268adf5c81b1daa772bdd614385c3bca531a Wed Oct 12 03:41:48 CEST 2005 Stephan Uphoff <ups@FreeBSD.org> Ensure that a thread stays on same CPU when calculating per CPU
TLB shootdown requirements. Otherwise a CPU may not get the needed
TLB invalidation.
The PTE valid and access flags can not be used here to avoid TLB
shootdowns unless sf->cpumask == all_cpus.
( Otherwise some CPUs may still hold an even older entry in the TLB)
Since sf_buf_alloc mappings are normally always used this is
also not really useful and presetting accessed and modified
allows the CPU to speculatively load the entry into the TLB.
Both bugs can cause random data corruption.
MFC after: 3 days
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