Re: computing drop-able caches

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Jan 28, 2016 at 03:42:53PM -0800, Daniel Walker wrote:
> "Currently there is no way to figure out the droppable pagecache size
> from the meminfo output. The MemFree size can shrink during normal
> system operation, when some of the memory pages get cached and is
> reflected in "Cached" field. Similarly for file operations some of
> the buffer memory gets cached and it is reflected in "Buffers" field.
> The kernel automatically reclaims all this cached & buffered memory,
> when it is needed elsewhere on the system. The only way to manually
> reclaim this memory is by writing 1 to /proc/sys/vm/drop_caches. "

[...]

> The point of the whole exercise is to get a better idea of free memory for
> our employer. Does it make sense to do this for computing free memory?

/proc/meminfo::MemAvailable was added for this purpose. See the doc
text in Documentation/filesystem/proc.txt.

It's an approximation, however, because this question is not easy to
answer. Pages might be in various states and uses that can make them
unreclaimable.
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux