Messages in this thread | | | Date | Thu, 6 Jan 2022 10:30:12 -1000 | From | Tejun Heo <> | Subject | Re: [RFC PATCH v2 1/2] kernfs: use kernfs_node specific mutex and spinlock. |
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Hello,
On Tue, Jan 04, 2022 at 08:40:30AM +0100, Greg KH wrote: > > We are seeing the launch time of some DB workloads adversely getting > > affected with this contention. > > What workloads? sysfs should NEVER be in the fast-path of any normal > operation, including booting. What benchmark or real-work is having > problems here?
In most systems, this shouldn't matter at all but sysfs and cgroupfs host a lot of statistics files which may be read regularly. It is conceivable that in large enough systems, the current locking scheme doesn't scale well enough. We should definitely measure the overhead and gains tho.
If this is something necessary, I think one possible solution is using hashed locks. I know that it isn't a popular choice but it makes sense given the constraints.
Thanks.
-- tejun
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