Re: Error unable to initialize cap quota of PD
Hi Norman, Am Freitag, 4. August 2017 11:56:38 CEST schrieb Norman Feske: While giving the scenario a quick spin, I observed another cap-quota issue, which is caused by the too low default value of 50 - the value used for all notes that lack an explicit 'caps' attribute. By setting this value to 100, the scenario starts up with NOVA on Qemu (tested on the current staging branch). However, apparently the launcher component also needs a few quota adjustments. I just fixed the corresponding parts in the commit [2] on the staging branch. May you give it a try? [2] https://github.com/genodelabs/genode/commit/94ef138f223ce6d9ab4a2608bc7cc73a76463335 I have tested it quickly, I checkout staging (commit 005820bb7bf6cb8b833b4227b8377984df5f9ceb) and build the launcher scenario. Now the scenario is started. Thanks Norman for your quick fix. The 'drivers' subsystem [5] is an init instance with 7 children (as of now). Hence, assigning 1000 caps to the subsystem seems to be reasonable. [5] repos/os/recipes/raw/drivers_interactive-pc/drivers.config Ok, drivers 'subsystem', that is what I missed. I haven't realized that the 'drivers.config' is a subsystem configuration. The limit of a component decreases each time it creates a session to a service where it transfers some of its own quota limit to the server. Initially, the limit of 'drivers' is 300. But as soon as 'drivers' creates sessions to the outside, its limit decreases step by step. You can think of the limit as the balance of a bank account. It you transfer money to another account, the balance decreases. The "used" value is the fraction of the quota that the component turned into actual resources (like RPC objects, dataspaces, signal handlers). To stay with the analogy, these are the purchased goods. Ok, limit means also the 'free cap ressouces' for the component and this will be transfered to other 'server components'. 'used' is only showing the using of RPC objects, dataspaces, signal handlers of the actual/current component, not also from the other 'server component'. Now I got it. I hope the above explanation sounds logical. Yes, many thanks for your detailed explanation. I think, I understood now. Thanks for bringing up this topic on the mailing list. You may not be the only one confused by the messages. Finally, let me compliment you for using the "diag" feature and for including all important details of your scenario at the start of your posting. No, problem. I'm also a C++ developer in my company and I get sometimes 'problems/crash dumps' from my colleagues/customer to fix them without any infos (build/version number, etc) :-). Cheers Jörg -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ genode-main mailing list genode-main@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/genode-main
Re: Error unable to initialize cap quota of PD
Hi Jörg, thanks for the detailed description of the issue. Please find my comments inline. I must admit that the launcher.run scenario is outdated since I use it very sporadically - only when working on one of the used components. Whenever I use it for this purpose, I use to run it on base-linux. So the current resource assignments are in general insufficient for other base platforms. It would be a good idea to move such kinds of "development-vehicle" scenarios to a dedicated place as discussed in [1] to spare people like you such negative surprises. [1] https://github.com/genodelabs/genode/issues/1372 > ... > Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded > during transfer_quota(4) > ... > > I want to fix that and try to understand what is the root cause for this > warning. I read the documentation, mainly 6.2.2. Resource assignment -> > Capability budget. When a client creates a new session, its tells its parent to transfer some of the client's resources to the server. In this case, the client is willing to lend 4 caps to the server. The common parent of the client and server will try to decrease the limit of the client by 4 and increase the limit of the server by the same value. However, since client has only 2 unused caps on its account, this attempt fails. This message points at a too scarce resource assignment for the 'drivers' subsystem. In the run script, there are merely 300 caps assigned to the 'drivers'. The value suffices for the little driver support needed for 'drivers_interactive-linux' but not for the much more complex 'drivers_interactive-pc' subsystem (as selected on NOVA). When setting the value to 1000 (as done in the wm.run script), the repeated error messages disappear. While giving the scenario a quick spin, I observed another cap-quota issue, which is caused by the too low default value of 50 - the value used for all notes that lack an explicit 'caps' attribute. By setting this value to 100, the scenario starts up with NOVA on Qemu (tested on the current staging branch). However, apparently the launcher component also needs a few quota adjustments. I just fixed the corresponding parts in the commit [2] on the staging branch. May you give it a try? [2] https://github.com/genodelabs/genode/commit/94ef138f223ce6d9ab4a2608bc7cc73a76463335 > But I'm not smart enough to understand this ;-), again I'm a newbie :-). > Is there some other documentation or another chapter that I should read > ? By the way, I read the hole old documentation 16.05 before. The release notes for 17.05 may hopefully be helpful [3]. [3] http://genode.org/documentation/release-notes/17.05#Assignment_and_trading_of_capability_quota > First, I didn't found any configuration for: > - platform_drv > - fb_drv > - usb_drv > - input_filter These components come from the 'drivers' subsystem, which is incorporated via the 'drivers_interactive-pc' depot package. The depot mechanism is brand new and may admittedly still be a bit rough around the edges. You can find its documentation at [4]. [4] http://genode.org/documentation/developer-resources/package_management > I think the root cause is following Error: > [init -> drivers] Error: acpi_drv: unable to initialize cap quota of PD > I understand that the acpi_drv component need X caps to transfer to the > drivers component. But how many caps ? You are spot on. The best practices regarding the assignment of cap quotas are still in flux. As a rule of thumb, I'd account 100 caps per component. The 'drivers' subsystem [5] is an init instance with 7 children (as of now). Hence, assigning 1000 caps to the subsystem seems to be reasonable. [5] repos/os/recipes/raw/drivers_interactive-pc/drivers.config > Then I try to understand the warning for example: > [init -> drivers] Warning: ps2_drv: assigned caps (60) exceed available > caps (0) > What I understand after reading the documentation: ps2_drv try to give > the drivers component 60 caps but they have only 0 caps left? It is a subsequent error of the one discussed above. During the creation of the 'drivers' children, the cap quota of the 'drivers' subsystem exhausts so that no caps are left for the PS2 driver. The problem is fixed with the increased quota of the 'drivers' subsystem. > Also I try to understand the following warning: > Warning: PD (init -> drivers) cap limit (used=44, limit=70) exceeded > during transfer_quota(28) > I understand: > The drivers component used 44 caps. The component need additional caps > of 28 but the limit of 70 caps is exceeded. (44 + 28 = 72 > 70) > Why limit 70? In the start configuration we set for the drivers > component 300 caps. The limit of a component decreases each time it creates a session to a service where it transfers some of its own quota limit to the server. Initially, the limit of 'drivers' is 300. But as soon as 'drivers' creates sessions to the outside, its limit decreases step by step. You can think of the limit as the balance of a
Error unable to initialize cap quota of PD
My setup/environment: - Source: Branch: master Date: Thu Jun 29 00:18:26 2017 +0200 commit 0d1be4abe2294155e36bc0eb0c1cd61499f08d93 - Target-genode-System: nova x86_64 - Host-System: genode-x86-gcc (GCC) 6.3.0 Ubuntu 17.04 QEMU emulator version 2.8.0(Debian 1:2.8+dfsg-3ubuntu2.3) Hi @all, I try to run following system scenario: make run/launcher KERNEL=nova but it fails with endless loop of following warning: ... Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) ... I want to fix that and try to understand what is the root cause for this warning. I read the documentation, mainly 6.2.2. Resource assignment -> Capability budget. But I'm not smart enough to understand this ;-), again I'm a newbie :-). Is there some other documentation or another chapter that I should read ? By the way, I read the hole old documentation 16.05 before. What I try/understand: In [BUILD_DIR]/var/run/launcher.run I see following: ... ... ... At start time I see following output: ... 5072 MiB RAM and 63254 caps assigned to init ... [init -> drivers] Warning: platform_drv: assigned caps (200) exceed available caps (123) [init -> drivers] Warning: fb_drv: assigned caps (100) exceed available caps (0) [init -> drivers] Warning: ps2_drv: assigned caps (60) exceed available caps (0) [init -> drivers] Warning: usb_drv: assigned caps (100) exceed available caps (0) [init -> drivers] Warning: input_filter: assigned caps (80) exceed available caps (0) Warning: PD (init -> drivers) cap limit (used=44, limit=70) exceeded during transfer_quota(28) [init -> drivers] Error: acpi_drv: unable to initialize cap quota of PD Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) [init -> drivers] resource_request: cap_quota=4 [init] child "drivers" requests resources: cap_quota=4 Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) [init -> drivers] resource_request: cap_quota=4 [init] child "drivers" requests resources: cap_quota=4 Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) [init -> drivers] resource_request: cap_quota=4 [init] child "drivers" requests resources: cap_quota=4 [init -> drivers] Warning: re-attempted CPU session request 2 times (args: diag=0, label="ps2_drv", ram_quota=36K, cap_quota=4) Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) [init -> drivers] resource_request: cap_quota=4 [init] child "drivers" requests resources: cap_quota=4 Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) [init -> drivers] resource_request: cap_quota=4 [init] child "drivers" requests resources: cap_quota=4 [init -> drivers] Warning: re-attempted CPU session request 4 times (args: diag=0, label="ps2_drv", ram_quota=36K, cap_quota=4) Warning: PD (init -> drivers) cap limit (used=44, limit=46) exceeded during transfer_quota(4) First, I didn't found any configuration for: - platform_drv - fb_drv - usb_drv - input_filter But I see at startup time that they are loaded into rom fs: ... :rom_fs: ROM modules: ... ROM: [7fb45000,7fb86db0) fb_drv ... ROM: [7ffe2000,7740) input_filter ... ROM: [7f6e3000,7f71d6d0) platform_drv ... ROM: [7fe03000,7fef5830) usb_drv ... I think the root cause is following Error: [init -> drivers] Error: acpi_drv: unable to initialize cap quota of PD I understand that the acpi_drv component need X caps to transfer to the drivers component. But how many caps ? Then I try to understand the warning for example: [init -> drivers] Warning: ps2_drv: assigned caps (60) exceed available caps (0) What I understand after reading the documentation: ps2_drv try to give the drivers component 60 caps but they have only 0 caps left? Also I try to understand the following warning: Warning: PD (init -> drivers) cap limit (used=44, limit=70) exceeded during transfer_quota(28) I understand: The drivers component used 44 caps. The component need additional caps of 28 but the limit of 70 caps is exceeded. (44 + 28 = 72 > 70) Why limit 70? In the start configuration we set for the drivers component 300 caps. So I read in the documentation, that we can enable a diagnostic mode for the PD session. I try this but even then, I did not understand the logs. Here what I get: ... Genode 17.05-86-g0d1be4abe 5072 MiB RAM and 63254 caps assigned to init PD (init -> drivers) consumed RPC cap (used=7, limit=280) PD (init -> drivers) consumed RPC cap (used=8, limit=280) PD (init -> drivers) consumed signal-source cap (used=10, limit=280) PD (init -> drivers) consumed RPC cap (used=11, limit=280) PD (init -> drivers) consumed signal-context cap (used=12, limit=280) PD (init -> drivers) transferred 3 caps to 'init' (used=12, limit=277) PD (init -> drivers)
