hi, tglx
thanks for your reply :)
On 2015年07月21日 16:10, Thomas Gleixner wrote:
> On Tue, 21 Jul 2015, Pan Xinhui wrote:
>> diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
>> index 188e3e0..f3c49fa 100644
>> --- a/arch/x86/mm/pat.c
>> +++ b/arch/x86/mm/pat.c
>> @@ -538,22 +538,20 @@ int reserve_memtype(u64 start, u64 end, enum
>> page_cache_mode req_type,
>> new->type = actual_type;
>>
>> spin_lock(&memtype_lock);
>> -
>> err = rbt_memtype_check_insert(new, new_type);
>> + actual_type = new->type;
>
> What's the point of this? new->type is set to actual_type 5 lines above.
191 int rbt_memtype_check_insert(struct memtype *new,
192 enum page_cache_mode *ret_type)
193 {
194 int err = 0;
195
196 err = memtype_rb_check_conflict(&memtype_rbroot, new->start, new->end,
197 new->type, ret_type);
198
199 if (!err) {
200 if (ret_type)
201 new->type = *ret_type;
202
So new->type might be set to *ret_type.
136 if (match->type != found_type && newtype == NULL)
137 goto failure;
138
139 dprintk("Overlap at 0x%Lx-0x%Lx\n", match->start, match->end);
140 found_type = match->type;
141
142 node = rb_next(&match->rb);
143 while (node) {
144 match = container_of(node, struct memtype, rb);
145
146 if (match->start >= end) /* Checked all possible matches */
147 goto success;
148
149 if (is_node_overlap(match, start, end) &&
150 match->type != found_type) {
151 goto failure;
152 }
153
154 node = rb_next(&match->rb);
155 }
156 success:
157 if (newtype)
158 *newtype = found_type;
So *ret_type might be set to found_type(match->type),
The call train is deep, it took me long time to review them.
As actual_type != new->type is possible, we need save new->type to actual_type.
thanks
xinhui
>
> Thanks,
>
> tglx
>
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