Messages in this thread | | | Date | Mon, 21 Jan 2019 16:47:15 -0500 | From | Vivek Goyal <> | Subject | Re: [RFC PATCH 0/3] cgroup: fsio throttle controller |
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On Sat, Jan 19, 2019 at 11:08:27AM +0100, Andrea Righi wrote:
[..] > Alright, let's skip the root cgroup for now. I think the point here is > if we want to provide sync() isolation among cgroups or not. > > According to the manpage: > > sync() causes all pending modifications to filesystem metadata and cached file data to be > written to the underlying filesystems. > > And: > According to the standard specification (e.g., POSIX.1-2001), sync() schedules the writes, but > may return before the actual writing is done. However Linux waits for I/O completions, and > thus sync() or syncfs() provide the same guarantees as fsync called on every file in the sys‐ > tem or filesystem respectively. > > Excluding the root cgroup, do you think a sync() issued inside a > specific cgroup should wait for I/O completions only for the writes that > have been generated by that cgroup?
Can we account I/O towards the cgroup which issued "sync" only if write rate of sync cgroup is higher than cgroup to which page belongs to. Will that solve problem, assuming its doable?
Vivek
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