Skip to content
Snippets Groups Projects
Commit 2fa044e5 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

XArray: Add cyclic allocation


This differs slightly from the IDR equivalent in five ways.

1. It can allocate up to UINT_MAX instead of being limited to INT_MAX,
   like xa_alloc().  Also like xa_alloc(), it will write to the 'id'
   pointer before placing the entry in the XArray.
2. The 'next' cursor is allocated separately from the XArray instead
   of being part of the IDR.  This saves memory for all the users which
   do not use the cyclic allocation API and suits some users better.
3. It returns -EBUSY instead of -ENOSPC.
4. It will attempt to wrap back to the minimum value on memory allocation
   failure as well as on an -EBUSY error, assuming that a user would
   rather allocate a small ID than suffer an ID allocation failure.
5. It reports whether it has wrapped, which is important to some users.

Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
parent a3e4d3f9
No related branches found
No related tags found
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment