Messages in this thread | | | Subject | Re: [PATCH 4/5] locking/lockdep: Reuse free chain_hlocks entries | From | Waiman Long <> | Date | Fri, 13 Dec 2019 11:05:12 -0500 |
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On 12/13/19 11:02 AM, Waiman Long wrote: > That is an interesting idea. It will eliminate the need of a separate > array to track the free chain_hlocks. However, if there are n chains > available, it will waste about 3n bytes of storage, on average. > > I have a slightly different idea. I will enforce a minimum allocation > size of 2. For a free block, the first 2 hlocks for each allocation > block will store a 32-bit integer (hlock[0] << 16)|hlock[1]: > > Bit 31: always 1 > Bits 24-30: block size > Bits 0-23: index to the next free block. > > In this way, the wasted space will be k bytes where k is the number of The wasted space should be 2k bytes. My mistake. > 1-entry chains. I don't think merging adjacent blocks will be that > useful at this point. We can always add this capability later on if it > is found to be useful.
Cheers, Longman
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