[PATCH 6.6.y] maple_tree: do not preallocate nodes for slot stores

Sidhartha Kumar sidhartha.kumar at oracle.com
Mon Dec 18 09:53:53 PST 2023


On 12/18/23 2:59 AM, Greg KH wrote:
> On Tue, Dec 12, 2023 at 11:52:55AM -0800, Sidhartha Kumar wrote:
>> mas_preallocate() defaults to requesting 1 node for preallocation and then
>> ,depending on the type of store, will update the request variable. There
>> isn't a check for a slot store type, so slot stores are preallocating the
>> default 1 node. Slot stores do not require any additional nodes, so add a
>> check for the slot store case that will bypass node_count_gfp(). Update
>> the tests to reflect that slot stores do not require allocations.
>>
>> User visible effects of this bug include increased memory usage from the
>> unneeded node that was allocated.
>>
>> Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing")
>> Cc: <stable at vger.kernel.org> # 6.6+
>> Signed-off-by: Sidhartha Kumar <sidhartha.kumar at oracle.com>
>> ---
>> This is a modified backport as the patch to fix this in upstream does not
>> apply to 6.6 because the node_end field was moved from the ma_wr_state to
>> the ma_state after 6.6.
> 
> What is the git commit id of this change in Linus's tree?

The patch is in akpm's mm-hotfixes-unstable tree and has not made it to Linus's 
tree yet.

Thanks,
Sid
> 
> thanks,
> 
> greg k-h




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