Revision be14eb619108fa8b7120eb2c42d66d5f623ae10e authored by Brian King on 10 September 2010, 07:03:21 UTC, committed by Jens Axboe on 10 September 2010, 07:03:21 UTC
While testing CPU DLPAR, the following problem was discovered. We were DLPAR removing the first CPU, which in this case was logical CPUs 0-3. CPUs 0-2 were already marked offline and we were in the process of offlining CPU 3. After marking the CPU inactive and offline in cpu_disable, but before the cpu was completely idle (cpu_die), we ended up in __make_request on CPU 3. There we looked at the topology map to see which CPU to complete the I/O on and found no CPUs in the cpu_sibling_map. This resulted in the block layer setting the completion cpu to be NR_CPUS, which then caused an oops when we tried to complete the I/O. Fix this by sanity checking the value we return from blk_cpu_to_group to be a valid cpu value. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
1 parent edce682
kmap_skb.h
#include <linux/highmem.h>
static inline void *kmap_skb_frag(const skb_frag_t *frag)
{
#ifdef CONFIG_HIGHMEM
BUG_ON(in_irq());
local_bh_disable();
#endif
return kmap_atomic(frag->page, KM_SKB_DATA_SOFTIRQ);
}
static inline void kunmap_skb_frag(void *vaddr)
{
kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ);
#ifdef CONFIG_HIGHMEM
local_bh_enable();
#endif
}
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