Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Paolo Bonzini
On 28/05/20 00:21, David Ahern wrote: > On 5/27/20 3:07 PM, Paolo Bonzini wrote: >> I see what you meant now. statsfs can also be used to enumerate objects >> if one is so inclined (with the prototype in patch 7, for example, each >> network interface becomes a directory). > > there are many use

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread David Ahern
On 5/27/20 3:07 PM, Paolo Bonzini wrote: > I see what you meant now. statsfs can also be used to enumerate objects > if one is so inclined (with the prototype in patch 7, for example, each > network interface becomes a directory). there are many use cases that have 100's to 1000's have network de

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Paolo Bonzini
On 27/05/20 23:27, Jakub Kicinski wrote: > On Wed, 27 May 2020 23:07:53 +0200 Paolo Bonzini wrote: >>> Again, I have little KVM knowledge, but BPF also uses a fd-based API, >>> and carries stats over the same syscall interface. >> >> Can BPF stats (for BPF scripts created by whatever process is r

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Jakub Kicinski
On Wed, 27 May 2020 23:07:53 +0200 Paolo Bonzini wrote: > > Again, I have little KVM knowledge, but BPF also uses a fd-based API, > > and carries stats over the same syscall interface. > > Can BPF stats (for BPF scripts created by whatever process is running in > the system) be collected by an e

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Andrew Lunn
On Tue, May 26, 2020 at 01:03:10PM +0200, Emanuele Giuseppe Esposito wrote: > There is currently no common way for Linux kernel subsystems to expose > statistics to userspace shared throughout the Linux kernel; subsystems have > to take care of gathering and displaying statistics by themselves, for

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Paolo Bonzini
On 27/05/20 22:23, Jakub Kicinski wrote: > On Wed, 27 May 2020 15:14:41 +0200 Emanuele Giuseppe Esposito wrote: >> Regarding the config, as I said the idea is to gather multiple >> subsystems' statistics, therefore there wouldn't be a single >> configuration method like in netlink. >> For example

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Jakub Kicinski
On Wed, 27 May 2020 15:14:41 +0200 Emanuele Giuseppe Esposito wrote: > Regarding the config, as I said the idea is to gather multiple > subsystems' statistics, therefore there wouldn't be a single > configuration method like in netlink. > For example in kvm there are file descriptors for configur

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Paolo Bonzini
On 27/05/20 15:33, Andrew Lunn wrote: >> I don't really know a lot about the networking subsystem, and as it was >> pointed out in another email on patch 7 by Andrew, networking needs to >> atomically gather and display statistics in order to make them consistent, >> and currently this is not suppo

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Andrew Lunn
> I don't really know a lot about the networking subsystem, and as it was > pointed out in another email on patch 7 by Andrew, networking needs to > atomically gather and display statistics in order to make them consistent, > and currently this is not supported by stats_fs but could be added in > f

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-27 Thread Emanuele Giuseppe Esposito
The file system is mounted on /sys/kernel/stats and would be already used by kvm. Statsfs was initially introduced by Paolo Bonzini [1]. What's the direct motivation for this work? Moving KVM stats out of debugfs? There's many reasons: one of these is not using debugfs for statistics, but

Re: [PATCH v3 0/7] Statsfs: a new ram-based file system for Linux kernel statistics

2020-05-26 Thread Jakub Kicinski
On Tue, 26 May 2020 13:03:10 +0200 Emanuele Giuseppe Esposito wrote: > There is currently no common way for Linux kernel subsystems to expose > statistics to userspace shared throughout the Linux kernel; subsystems have > to take care of gathering and displaying statistics by themselves, for > exam