55 строки
1.4 KiB
C
55 строки
1.4 KiB
C
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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/* Allocate an array of spinlocks to be accessed by a hash. Two arguments
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* indicate the number of elements to allocate in the array. max_size
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* gives the maximum number of elements to allocate. cpu_mult gives
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* the number of locks per CPU to allocate. The size is rounded up
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* to a power of 2 to be suitable as a hash table.
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*/
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int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
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size_t max_size, unsigned int cpu_mult, gfp_t gfp)
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{
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spinlock_t *tlocks = NULL;
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unsigned int i, size;
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#if defined(CONFIG_PROVE_LOCKING)
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unsigned int nr_pcpus = 2;
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#else
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unsigned int nr_pcpus = num_possible_cpus();
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#endif
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if (cpu_mult) {
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nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);
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size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);
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} else {
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size = max_size;
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}
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if (sizeof(spinlock_t) != 0) {
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if (gfpflags_allow_blocking(gfp))
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tlocks = kvmalloc(size * sizeof(spinlock_t), gfp);
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else
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tlocks = kmalloc_array(size, sizeof(spinlock_t), gfp);
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if (!tlocks)
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return -ENOMEM;
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for (i = 0; i < size; i++)
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spin_lock_init(&tlocks[i]);
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}
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*locks = tlocks;
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*locks_mask = size - 1;
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return 0;
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}
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EXPORT_SYMBOL(alloc_bucket_spinlocks);
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void free_bucket_spinlocks(spinlock_t *locks)
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{
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kvfree(locks);
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}
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EXPORT_SYMBOL(free_bucket_spinlocks);
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