Re: [systemd-devel] UDEV popen/system returns error if called from the program (RUN option)
> On Mar 3, 2020, at 3:43 PM, Josef Moellers wrote: > > On 03.03.20 12:26, Ilya Matveychikov wrote: >> Dear Lennart, >> >> Thank you for the reply. >> >>> On Mar 3, 2020, at 12:54 PM, Lennart Poettering >>> wrote: >>> >>> On Mo, 02.03.20 00:35, Ilya Matveychikov (matvejchi...@gmail.com) wrote: >>> Hey guys, I’m not sure is it the right place to ask about the UDEV or not. Anyways, I have a problem with running custom program from the UDEV rule (RUN+= option). The problem is somehow related to fork/exec, I can’t tell for sure. My code (this custom “RUN+=“-binary) using popen() to call external program and get the result using stream. Once I run this custom program alone it works perfectly well. But once it is executed under the systemd/udev via the rule this popen() returns error with the code ENOMEM which is very strange for me as the system has like 32Gb of RAM. The same happen with system() ... Do you guys have any glue of what the heck is going on? Are there any constraints on what can be done in “programs”? >>> >>> We enforce a limit on the number of processes/threads forked off >>> services, and udevd has a limt set like that too, via the TasksMax= >>> setting in its unit file. Maybe you are leaking processes/threads >>> somehow and hit that limit? >> >> I don’t do any multithreading in my program, except some popen()’s .. >> >> My system (archlinux) has "TasksMax=infinity” line in file: >> /usr/lib/systemd/system/sysinit.target.wants/systemd-udev.service >> >> Any other tips? > Just a shot in the dark: do you pclose() all popen()s? I hope I do pclose() all of them. Anyway, the same behavior I’m getting with trying to do system(“ls -al / >/xxx”) before any popen(), just in the beginning of the program. It fails! > > Josef > -- > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5 > 90409 Nürnberg > Germany > > (HRB 36809, AG Nürnberg) > Geschäftsführer: Felix Imendörffer > ___ > systemd-devel mailing list > systemd-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] UDEV popen/system returns error if called from the program (RUN option)
On 03.03.20 12:26, Ilya Matveychikov wrote: > Dear Lennart, > > Thank you for the reply. > >> On Mar 3, 2020, at 12:54 PM, Lennart Poettering >> wrote: >> >> On Mo, 02.03.20 00:35, Ilya Matveychikov (matvejchi...@gmail.com) wrote: >> >>> Hey guys, >>> >>> I’m not sure is it the right place to ask about the UDEV or not. >>> >>> Anyways, I have a problem with running custom program from the UDEV rule >>> (RUN+= option). >>> The problem is somehow related to fork/exec, I can’t tell for sure. >>> >>> My code (this custom “RUN+=“-binary) using popen() to call external program >>> and get the result using stream. Once I run this custom program alone it >>> works >>> perfectly well. But once it is executed under the systemd/udev via the rule >>> this popen() returns error with the code ENOMEM which is very strange for me >>> as the system has like 32Gb of RAM. >>> >>> The same happen with system() ... >>> >>> Do you guys have any glue of what the heck is going on? >>> Are there any constraints on what can be done in “programs”? >> >> We enforce a limit on the number of processes/threads forked off >> services, and udevd has a limt set like that too, via the TasksMax= >> setting in its unit file. Maybe you are leaking processes/threads >> somehow and hit that limit? > > I don’t do any multithreading in my program, except some popen()’s .. > > My system (archlinux) has "TasksMax=infinity” line in file: > /usr/lib/systemd/system/sysinit.target.wants/systemd-udev.service > > Any other tips? Just a shot in the dark: do you pclose() all popen()s? Josef -- SUSE Software Solutions Germany GmbH Maxfeldstr. 5 90409 Nürnberg Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] UDEV popen/system returns error if called from the program (RUN option)
Dear Lennart, Thank you for the reply. > On Mar 3, 2020, at 12:54 PM, Lennart Poettering > wrote: > > On Mo, 02.03.20 00:35, Ilya Matveychikov (matvejchi...@gmail.com) wrote: > >> Hey guys, >> >> I’m not sure is it the right place to ask about the UDEV or not. >> >> Anyways, I have a problem with running custom program from the UDEV rule >> (RUN+= option). >> The problem is somehow related to fork/exec, I can’t tell for sure. >> >> My code (this custom “RUN+=“-binary) using popen() to call external program >> and get the result using stream. Once I run this custom program alone it >> works >> perfectly well. But once it is executed under the systemd/udev via the rule >> this popen() returns error with the code ENOMEM which is very strange for me >> as the system has like 32Gb of RAM. >> >> The same happen with system() ... >> >> Do you guys have any glue of what the heck is going on? >> Are there any constraints on what can be done in “programs”? > > We enforce a limit on the number of processes/threads forked off > services, and udevd has a limt set like that too, via the TasksMax= > setting in its unit file. Maybe you are leaking processes/threads > somehow and hit that limit? I don’t do any multithreading in my program, except some popen()’s .. My system (archlinux) has "TasksMax=infinity” line in file: /usr/lib/systemd/system/sysinit.target.wants/systemd-udev.service Any other tips? > > Lennart > > -- > Lennart Poettering, Berlin ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] UDEV popen/system returns error if called from the program (RUN option)
On Mo, 02.03.20 00:35, Ilya Matveychikov (matvejchi...@gmail.com) wrote: > Hey guys, > > I’m not sure is it the right place to ask about the UDEV or not. > > Anyways, I have a problem with running custom program from the UDEV rule > (RUN+= option). > The problem is somehow related to fork/exec, I can’t tell for sure. > > My code (this custom “RUN+=“-binary) using popen() to call external program > and get the result using stream. Once I run this custom program alone it works > perfectly well. But once it is executed under the systemd/udev via the rule > this popen() returns error with the code ENOMEM which is very strange for me > as the system has like 32Gb of RAM. > > The same happen with system() ... > > Do you guys have any glue of what the heck is going on? > Are there any constraints on what can be done in “programs”? We enforce a limit on the number of processes/threads forked off services, and udevd has a limt set like that too, via the TasksMax= setting in its unit file. Maybe you are leaking processes/threads somehow and hit that limit? Lennart -- Lennart Poettering, Berlin ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
