Re: [PATCH 1/3] xvmalloc memory allocator

From: Nitin Gupta
Date: Sun Mar 29 2009 - 07:23:51 EST


Marcin Slusarz wrote:
Nitin Gupta wrote:
+static void stat_inc(u64 *value)
+{
+ (*value)++;
+}
+
+static void stat_dec(u64 *value)
+{
+ (*value)--;
+}

Why not open code it?



This looks nicer, doesn't it?


+
+static u32 test_flag(struct block_header *block, enum blockflags flag)
+{
+ return block->prev & (1 << flag);
+}
+
+static void set_flag(struct block_header *block, enum blockflags flag)
+{
+ block->prev |= (1 << flag);
+}
+
+static void clear_flag(struct block_header *block, enum blockflags flag)
+{
+ block->prev &= ~(1 << flag);
+}

Why don't you use test_bit / __set_bit / __clear_bit directly?


block->prev is 16 bits. __set_bit() etc. need unsigned long pointer.

+struct xv_pool *xv_create_pool(void)
+{
+ int i;
+ u32 ovhd_size;
+ struct xv_pool *pool;
+
+ ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);
+ pool = kmalloc(ovhd_size, GFP_KERNEL);
+ if (!pool)
+ return NULL;
+
+ memset(pool, 0, ovhd_size);

Please use kzalloc.


Ok...

+
+ for (i = 0; i < NUM_FREE_LISTS; i++) {
+ pool->freelist[i].pagenum = 0;
+ pool->freelist[i].offset = 0;
+ }

It was already zeroed by memset.

Remains from earlier code; we used to set it to 'INVALID_PGNUM'.
Ok, will remove this.


Thanks for review.
Nitin
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