Messages in this thread |  | | Date | Thu, 24 Aug 2000 18:35:46 -0400 | From | David Mansfield <> | Subject | Re: ll_rw_blk.c fails to merge requests. Help! |
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Jens Axboe wrote: > > Okay, here's a new version. The pending list always contains requests > from the write list, so we can use list_splice. We batch a quarter > the size freelist, i.e. half the size of the write list -- whether > that is a good number, I don't know. I suspect it should be less > than that.
To preface this, I don't really know what I'm talking about so ignore me if this is stupid.
I understand you are coalescing the freed requests to add them back to the freelist in a batch, but this is done only for 'write' requests, so it makes sense that the wake_up is postponed until the list_splice of the pending_list into the write_list.
But, it looks like with your patch, if the req->free_list is the 'read' freelist the wake_up will *never* happen (unlike in the original version). Is this missing wake_up intended?
(you mentioned in an earlier post that read requests can be stolen from the write free_list, I suppose if your code is correct it has something to do with this fact :-) as I said, I know next to nothing here, just learning)
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