Messages in this thread | | | Date | Fri, 5 Aug 2016 22:07:37 +1000 | From | Dave Chinner <> | Subject | Re: [bug, 4.8] /proc/meminfo: counter values are very wrong |
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On Fri, Aug 05, 2016 at 09:59:35PM +1000, Dave Chinner wrote: > On Fri, Aug 05, 2016 at 11:54:17AM +0100, Mel Gorman wrote: > > On Fri, Aug 05, 2016 at 09:11:10AM +1000, Dave Chinner wrote: > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > > > index fb975cec3518..baa97da3687d 100644 > > > > --- a/mm/page_alloc.c > > > > +++ b/mm/page_alloc.c > > > > @@ -4064,7 +4064,7 @@ long si_mem_available(void) > > > > int lru; > > > > > > > > for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++) > > > > - pages[lru] = global_page_state(NR_LRU_BASE + lru); > > > > + pages[lru] = global_node_page_state(NR_LRU_BASE + lru); > > > > > > > > for_each_zone(zone) > > > > wmark_low += zone->watermark[WMARK_LOW]; > > > > > > OK, that makes the /proc accounting match the /sys per-node > > > accounting, but the output still looks wrong. I remove files with > > > cached pages from the filesystem (i.e. invalidate and free them), > > > yet they are apparrently still accounted as being on the > > > active/inactive LRU. > > > > > > Reboot, then run dbench for a minute: > > > > > > $ sudo mkfs.xfs -f /dev/pmem1 > > > meta-data=/dev/pmem1 isize=512 agcount=4, agsize=524288 blks > > > = sectsz=4096 attr=2, projid32bit=1 > > > = crc=1 finobt=1, sparse=0 > > > data = bsize=4096 blocks=2097152, imaxpct=25 > > > = sunit=0 swidth=0 blks > > > naming =version 2 bsize=4096 ascii-ci=0 ftype=1 > > > log =internal log bsize=4096 blocks=2560, version=2 > > > = sectsz=4096 sunit=1 blks, lazy-count=1 > > > realtime =none extsz=4096 blocks=0, rtextents=0 > > > $ sudo mount /dev/pmem1 /mnt/scratch > > > $ sudo dbench -t 60 -D /mnt/scratch/ 16 > > > dbench version 4.00 - Copyright Andrew Tridgell 1999-2004 > > > > > > > Is there any chance this is related to pmem1? > > Nope, just reproduced it on /dev/vdc to confirm.
And same thing on a different machine, using iscsi storage.
Also, I just noticed that unmounting the filesystem doesn't clean it up - the inactive/active LRU usage is still there.
Ah, maybe this is a result of the all the block layer request flag changes and that's screwing up the page accounting. I'll get back to you on that - not going to try to test that now as it's almost bed time.
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
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