Messages in this thread | | | From | Nikita Danilov <> | Date | Thu, 6 Jul 2006 00:05:58 +0400 | Subject | Re: [PATCH] mm: moving dirty pages balancing to pdfludh entirely |
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Ananiev, Leonid I writes: > Nikita Danilov writes: > > Exactly to the contrary: as I explained to you, if you have more > devices > > than pdflush threads > I do not believe that Bret Towe has more devices than > MAX_PDFLUSH_THREADS=8.
Some people do, should they suffer? :-)
> > > See how wbc.nr_to_write is set up by balance_dirty_pages(). > It is number TO write but I said about number after what user has to > write-out all dirty pages.
Not _all_, only nr_to_write of them:
if (pages_written >= write_chunk) break; /* We've done our duty */
> > > imagine that MAX_PDFLUSH_THREADS equals 1 > Imagine that CONFIG_NR_CPUS=1 for smp. > Kernel has a lot of "big enough" constants.
Then why introduce more of them?
In current design each thread is responsible for write-out. This means that write-out concurrency level scales together with the number of writers. You propose to limit write-out concurrency by MAX_PDFLUSH_THREADS. Obviously this is an artificial limit that will be sub-optimal sometimes.
> > Leonid
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