Hi Kent, sorry to bother you again. i got another question. it's about the bucket->pin. Can you explain what's the usage for this data member? i see only bucket with pin value "0" can be invalidated. And only "0" valued pin bucket's prio will be decreased within the bch_rescale_priorities(). But every time when you write data to bucket, you increase that bucket's pin, and i did not see when it will be decreased. This makes me a little confused. Or do i miss anything where you might reset it?
i am appreciated for your help. Thanks, Sheng On Thu, Jul 11, 2013 at 10:41 PM, Kent Overstreet <[email protected]> wrote: > On Thu, Jul 11, 2013 at 10:29:23PM -0400, sheng qiu wrote: >> sure, in your btree.c code, when you do btree gc, you update the >> bucket's used sectors by min(unsigned, GC_SECTORS_USED(b)+key_size(), >> 1<<14-1). this might get you larger than the bucket size. since the >> newly allocated bucket is set to bucket size already. so each round >> you will accumulate the key_size(). i print the information at that >> point, and see GC_SECTORS_USED > bucket size. > > Hey, I think you're right - btree_gc_start() is supposed to be zeroing > out GC_SECTORS_USED() (the same place it does SET_GC_MARK(b, > GC_MARK_RECLAIMABLE)) - but that's missing. Thanks! -- Sheng Qiu Texas A & M University Room 332B Wisenbaker email: [email protected] College Station, TX 77843-3259 -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
