I think the particular thresholds of opens and inode count are
interacting in a way we'd like to change. I think it might make sense
to delegate the various decision points to maybe a vector of strategy
functions, letting more varied approaches compete?
Matt
On Thu, Aug 10, 2017 at 7:12 PM, Pradeep <pradeep.tho...@gmail.com> wrote:
> Debugged this a little more. It appears that the entries that can be reaped
> are not at the LRU position (head) of the L1 queue. So those can be free'd
> later by lru_run(). I don't see it happening either for some reason.
>
> (gdb) p LRU[1].L1
> $29 = {q = {next = 0x7fb459e71960, prev = 0x7fb3ec3c0d30}, id =
> LRU_ENTRY_L1, size = 260379}
>
> head of the list is an entry with refcnt 2; but there are several entries
> with refcnt 1.
>
> (gdb) p *(mdcache_lru_t *)0x7fb459e71960
> $30 = {q = {next = 0x7fb43ddea8a0, prev = 0x7d68a0 <LRU+224>}, qid =
> LRU_ENTRY_L1, refcnt = 2, flags = 0, lane = 1, cf = 2}
> (gdb) p *(mdcache_lru_t *)0x7fb43ddea8a0
> $31 = {q = {next = 0x7fb3f041f9a0, prev = 0x7fb459e71960}, qid =
> LRU_ENTRY_L1, refcnt = 1, flags = 0, lane = 1, cf = 0}
> (gdb) p *(mdcache_lru_t *)0x7fb3f041f9a0
> $32 = {q = {next = 0x7fb466960200, prev = 0x7fb43ddea8a0}, qid =
> LRU_ENTRY_L1, refcnt = 1, flags = 0, lane = 1, cf = 0}
> (gdb) p *(mdcache_lru_t *)0x7fb466960200
> $33 = {q = {next = 0x7fb451e20570, prev = 0x7fb3f041f9a0}, qid =
> LRU_ENTRY_L1, refcnt = 2, flags = 0, lane = 1, cf = 1}
>
> The entries with refcnt 1 are moved to L2 by the background thread
> (lru_run). However it does it only of the open file count is greater than
> low water mark. In my case, the open_fd_count is not high; so lru_run()
> doesn't call lru_run_lane() to demote those entries to L2. What is the best
> approach to handle this scenario?
>
> Thanks,
> Pradeep
>
>
>
> On Mon, Aug 7, 2017 at 6:08 AM, Daniel Gryniewicz <d...@redhat.com> wrote:
>>
>> It never has been. In cache_inode, a pin-ref kept it from being
>> reaped, now any ref beyond 1 keeps it.
>>
>> On Fri, Aug 4, 2017 at 1:31 PM, Frank Filz <ffilz...@mindspring.com>
>> wrote:
>> >> I'm hitting a case where mdcache keeps growing well beyond the high
>> >> water
>> >> mark. Here is a snapshot of the lru_state:
>> >>
>> >> 1 = {entries_hiwat = 100000, entries_used = 2306063, chunks_hiwat =
>> > 100000,
>> >> chunks_used = 16462,
>> >>
>> >> It has grown to 2.3 million entries and each entry is ~1.6K.
>> >>
>> >> I looked at the first entry in lane 0, L1 queue:
>> >>
>> >> (gdb) p LRU[0].L1
>> >> $9 = {q = {next = 0x7fad64256f00, prev = 0x7faf21a1bc00}, id =
>> >> LRU_ENTRY_L1, size = 254628}
>> >> (gdb) p (mdcache_entry_t *)(0x7fad64256f00-1024)
>> >> $10 = (mdcache_entry_t *) 0x7fad64256b00
>> >> (gdb) p $10->lru
>> >> $11 = {q = {next = 0x7fad65ea0f00, prev = 0x7d67c0 <LRU>}, qid =
>> >> LRU_ENTRY_L1, refcnt = 2, flags = 0, lane = 0, cf = 0}
>> >> (gdb) p $10->fh_hk.inavl
>> >> $13 = true
>> >
>> > The refcount 2 prevents reaping.
>> >
>> > There could be a refcount leak.
>> >
>> > Hmm, though, I thought the entries_hwmark was a hard limit, guess not...
>> >
>> > Frank
>> >
>> >> Lane 1:
>> >> (gdb) p LRU[1].L1
>> >> $18 = {q = {next = 0x7fad625c0300, prev = 0x7faec08c5100}, id =
>> >> LRU_ENTRY_L1, size = 253006}
>> >> (gdb) p (mdcache_entry_t *)(0x7fad625c0300 - 1024)
>> >> $21 = (mdcache_entry_t *) 0x7fad625bff00
>> >> (gdb) p $21->lru
>> >> $22 = {q = {next = 0x7fad66fce600, prev = 0x7d68a0 <LRU+224>}, qid =
>> >> LRU_ENTRY_L1, refcnt = 2, flags = 0, lane = 1, cf = 1}
>> >>
>> >> (gdb) p $21->fh_hk.inavl
>> >> $24 = true
>> >>
>> >> As per LRU_ENTRY_RECLAIMABLE(), these entry should be reclaimable. Not
>> >> sure why it is not able to claim it. Any ideas?
>> >>
>> >> Thanks,
>> >> Pradeep
>> >>
>> >>
>> >
>> > ----------------------------------------------------------------------------
>> > --
>> >> Check out the vibrant tech community on one of the world's most
>> >> engaging
>> >> tech sites, Slashdot.org! http://sdm.link/slashdot
>> >> _______________________________________________
>> >> Nfs-ganesha-devel mailing list
>> >> Nfs-ganesha-devel@lists.sourceforge.net
>> >> https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
>> >
>> >
>> > ---
>> > This email has been checked for viruses by Avast antivirus software.
>> > https://www.avast.com/antivirus
>> >
>> >
>> >
>> > ------------------------------------------------------------------------------
>> > Check out the vibrant tech community on one of the world's most
>> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> > _______________________________________________
>> > Nfs-ganesha-devel mailing list
>> > Nfs-ganesha-devel@lists.sourceforge.net
>> > https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
>
>
>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> Nfs-ganesha-devel mailing list
> Nfs-ganesha-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
>
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Nfs-ganesha-devel mailing list
Nfs-ganesha-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
