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author | Matthew Wilcox <willy@infradead.org> | 2018-07-04 10:50:12 -0400 |
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committer | Matthew Wilcox <willy@infradead.org> | 2018-10-21 10:46:32 -0400 |
commit | 371c752dc66948714ee3b66c3306f3ff1ff71d2e (patch) | |
tree | a9707d94787474e20b4efcd9bc81d5e6e1328a66 /lib/test_xarray.c | |
parent | 3d5bd6e1a04ae779bc5e0de9ba2e92aa55c40fe8 (diff) | |
download | lwn-371c752dc66948714ee3b66c3306f3ff1ff71d2e.tar.gz lwn-371c752dc66948714ee3b66c3306f3ff1ff71d2e.zip |
xarray: Track free entries in an XArray
Add the optional ability to track which entries in an XArray are free
and provide xa_alloc() to replace most of the functionality of the IDR.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'lib/test_xarray.c')
-rw-r--r-- | lib/test_xarray.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/lib/test_xarray.c b/lib/test_xarray.c index 6aafd411a5c3..a752e6a37e6f 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -33,6 +33,15 @@ static void *xa_store_index(struct xarray *xa, unsigned long index, gfp_t gfp) return xa_store(xa, index, xa_mk_value(index & LONG_MAX), gfp); } +static void xa_alloc_index(struct xarray *xa, unsigned long index, gfp_t gfp) +{ + u32 id = 0; + + XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, xa_mk_value(index & LONG_MAX), + gfp) != 0); + XA_BUG_ON(xa, id != index); +} + static void xa_erase_index(struct xarray *xa, unsigned long index) { XA_BUG_ON(xa, xa_erase(xa, index) != xa_mk_value(index & LONG_MAX)); @@ -404,6 +413,57 @@ static noinline void check_multi_store(struct xarray *xa) #endif } +static DEFINE_XARRAY_ALLOC(xa0); + +static noinline void check_xa_alloc(void) +{ + int i; + u32 id; + + /* An empty array should assign 0 to the first alloc */ + xa_alloc_index(&xa0, 0, GFP_KERNEL); + + /* Erasing it should make the array empty again */ + xa_erase_index(&xa0, 0); + XA_BUG_ON(&xa0, !xa_empty(&xa0)); + + /* And it should assign 0 again */ + xa_alloc_index(&xa0, 0, GFP_KERNEL); + + /* The next assigned ID should be 1 */ + xa_alloc_index(&xa0, 1, GFP_KERNEL); + xa_erase_index(&xa0, 1); + + /* Storing a value should mark it used */ + xa_store_index(&xa0, 1, GFP_KERNEL); + xa_alloc_index(&xa0, 2, GFP_KERNEL); + + /* If we then erase 0, it should be free */ + xa_erase_index(&xa0, 0); + xa_alloc_index(&xa0, 0, GFP_KERNEL); + + xa_erase_index(&xa0, 1); + xa_erase_index(&xa0, 2); + + for (i = 1; i < 5000; i++) { + xa_alloc_index(&xa0, i, GFP_KERNEL); + } + + xa_destroy(&xa0); + + id = 0xfffffffeU; + XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, UINT_MAX, xa_mk_value(0), + GFP_KERNEL) != 0); + XA_BUG_ON(&xa0, id != 0xfffffffeU); + XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, UINT_MAX, xa_mk_value(0), + GFP_KERNEL) != 0); + XA_BUG_ON(&xa0, id != 0xffffffffU); + XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, UINT_MAX, xa_mk_value(0), + GFP_KERNEL) != -ENOSPC); + XA_BUG_ON(&xa0, id != 0xffffffffU); + xa_destroy(&xa0); +} + static noinline void __check_store_iter(struct xarray *xa, unsigned long start, unsigned int order, unsigned int present) { @@ -849,6 +909,7 @@ static int xarray_checks(void) check_cmpxchg(&array); check_reserve(&array); check_multi_store(&array); + check_xa_alloc(); check_find(&array); check_destroy(&array); check_move(&array); |