archive mirror
 help / color / mirror / Atom feed
* Re: Overlayfs performance issue
       [not found] <>
@ 2021-01-21  7:45 ` Miklos Szeredi
  0 siblings, 0 replies; only message in thread
From: Miklos Szeredi @ 2021-01-21  7:45 UTC (permalink / raw)
  To: garyhuang; +Cc: linux-unionfs

On Wed, Jan 20, 2021 at 11:54 PM garyhuang <> wrote:
> Hi Miklos,
> Have you ever come into this?
> 1. dockerd with overlay2
>    a. Running nginx in container mounting the host directory which contains the file to be accessed (docker -v xxx:xxx)
>    b. Running nginx in container mounting the host file directly
>    The RPS varies too much (RPS(a) < RPS(b)), the more the workers are, the bigger the discount is
> 2. dockerd with devicemapper
>    Running nginx in container with both the same mounting scenarios, the RPS is not discounted
> 3. nginx on host, no performance discounted too. The RPS equals to container with devicemapper.
> It is kernel related with big extra spinlock consumption observed by perf when running dockerd with overlayfs even the file is mounted from outside host path.

It's not clear where the contention is coming from.  Can you get some
detail from the perf trace where we can see which overlayfs functions
are involved?


^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2021-01-21  7:47 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <>
2021-01-21  7:45 ` Overlayfs performance issue Miklos Szeredi

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).