Simplify vm_radix_insert()
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Authored by alc on Nov 28 2016, 6:00 PM.

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kib
markj

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rS309365: During vm_page_cache()'s call to vm_radix_insert(), if vm_page_alloc() was

Summary

During vm_page_cache()'s call to vm_radix_insert(), if vm_page_alloc() was called to allocate a new page of radix trie nodes, there could be a call to vm_radix_remove() on the same trie (of PG_CACHED pages) as the in-progress vm_radix_insert(). With the removal of PG_CACHED pages, we can simplify vm_radix_insert() and vm_radix_remove() by removing the flags on the root of the trie that were used to detect this case and the code for restarting the vm_radix_insert() at the trie's root when it happened.

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rS FreeBSD src repository - subversion

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alc updated this revision to Diff 22546.Nov 28 2016, 6:00 PM

alc retitled this revision from to Simplify vm_radix_insert().

alc updated this object.

alc edited the test plan for this revision. (Show Details)

alc added reviewers: kib, markj.

alc added a subscriber: pho.

kib accepted this revision.Nov 28 2016, 6:07 PM

kib edited edge metadata.

This revision is now accepted and ready to land.Nov 28 2016, 6:07 PM

Three of the pmap implementations use radix tries to maintain a collection of page table pages. I found that none of them ever initialized the "rt_flags" field. A radix trie root is initialized by direct assignment to its field(s) in the user, and not with a "method".

markj accepted this revision.Nov 28 2016, 6:17 PM

markj edited edge metadata.

Peter, could you please test this patch.

In D8664#179617, @alc wrote:

Peter, could you please test this patch.

Sure. No problems found on amd64. Still need to do some more tests on i386.

In D8664#179751, @pho wrote:

In D8664#179617, @alc wrote:

Peter, could you please test this patch.

Sure. No problems found on amd64. Still need to do some more tests on i386.