mmap huge page and MAP_SYNC flag support
Hi,How do I enable the MAP_SYNC flag in mmap for linux 4.15, my code does not compile with that flag on linux 4.15.0-041500rc7-generic #201801072330 Also, how do I make mmap support map size of 2GB or larger, currently the call to mmap fails with mapsize of 2GB. thanks, David
On Thu, 12 Jul 2018 18:44:43 -0000, David Frank said:
Hi,How do I enable the MAP_SYNC flag in mmap for linux 4.15, my code does not compile with that flag on linux 4.15.0-041500rc7-generic #201801072330
Get your distro to ship an update to /usr/include/linux (kernel-headers) that contains the flag. Your kernel supports it, but your toolchain doesn't until you get an include file that includes the update for MAP_SYNC
Also, how do I make mmap support map size of 2GB or larger, currently the call to mmap fails with mapsize of 2GB.
What error code does it fail with?
Thanks Valdis.Looks like the failure is that I can not write to a 2GB buffer (char bf[2GB size]).Where do I get the distro include file? On Thursday, July 12, 2018, 2:58:49 PM EDT, valdis.kletnieks@vt.edu <valdis.kletnieks@vt.edu> wrote: On Thu, 12 Jul 2018 18:44:43 -0000, David Frank said:
Hi,How do I enable the MAP_SYNC flag in mmap for linux 4.15, my code does not compile with that flag on linux 4.15.0-041500rc7-generic #201801072330
Get your distro to ship an update to /usr/include/linux (kernel-headers) that contains the flag. Your kernel supports it, but your toolchain doesn't until you get an include file that includes the update for MAP_SYNC
Also, how do I make mmap support map size of 2GB or larger, currently the call to mmap fails with mapsize of 2GB.
What error code does it fail with? _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
On Thu, 12 Jul 2018 20:10:36 -0000, David Frank said:
Thanks Valdis.Looks like the failure is that I can not write to a 2GB buffer (char bf[2GB size]).Where do I get the distro include file?
From the same exact place you got the distro kernel from. (I'm guessing it's a distro kernel from the -generic in the uname -r). If you built it yourself from a Linus source git/tarball, 'make headers_install' will do it, but note that if the rest of the distro install still thinks you have a distro kernel-headers installed, the package management system may whine....
I got it from hereHow To Install Kernel 4.15 RC7 on Ubuntu, Linux Mint, Elementary OS And Other Ubuntu Derivatives | LinuxG.net | | | | How To Install Kernel 4.15 RC7 on Ubuntu, Linux Mint, Elementary OS And ... | | | no headers On Thursday, July 12, 2018, 4:22:33 PM EDT, <valdis.kletnieks@vt.edu> wrote: On Thu, 12 Jul 2018 20:10:36 -0000, David Frank said:
Thanks Valdis.Looks like the failure is that I can not write to a 2GB buffer (char bf[2GB size]).Where do I get the distro include file?
From the same exact place you got the distro kernel from. (I'm guessing it's a distro kernel from the -generic in the uname -r). If you built it yourself from a Linus source git/tarball, 'make headers_install' will do it, but note that if the rest of the distro install still thinks you have a distro kernel-headers installed, the package management system may whine...._______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
On Thu, 12 Jul 2018 20:33:32 -0000, David Frank said:
I got it from hereHow To Install Kernel 4.15 RC7 on Ubuntu, Linux Mint, Elementary OS And Other Ubuntu Derivatives | LinuxG.net
Looks like you got the linux-image-... .deb but didn't do the linux-headers-... .deb(s). (And I have no idea why they list 2 different linux-headers .deb's. Anybody understand Ubuntu's mindset enough to explain that? I get paid to deal with RedHat-based stuff...)
By the way, when I havemmap(NULL, MAPSIZE, PROT_WRITE_|PROT_READ, MAP_HUGETLB|MAP_PRIVATE, fd, 0):where MAPSIZE= 2GB,it fails witherror = 22, invalid argument, without MAP_HUGETLB, it was ok. On Thursday, July 12, 2018, 4:44:35 PM EDT, <valdis.kletnieks@vt.edu> wrote: On Thu, 12 Jul 2018 20:33:32 -0000, David Frank said:
I got it from hereHow To Install Kernel 4.15 RC7 on Ubuntu, Linux Mint, Elementary OS And Other Ubuntu Derivatives | LinuxG.net
Looks like you got the linux-image-... .deb but didn't do the linux-headers-... .deb(s). (And I have no idea why they list 2 different linux-headers .deb's. Anybody understand Ubuntu's mindset enough to explain that? I get paid to deal with RedHat-based stuff...)_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Tried everything in here:How do I install kernel header files? | | | | | | | | | | | How do I install kernel header files? i want to write a device driver but not able to find the header file can someone please help me find them?Also i... | | | nothing worked. On Thursday, July 12, 2018, 2:58:49 PM EDT, valdis.kletnieks@vt.edu <valdis.kletnieks@vt.edu> wrote: On Thu, 12 Jul 2018 18:44:43 -0000, David Frank said:
Hi,How do I enable the MAP_SYNC flag in mmap for linux 4.15, my code does not compile with that flag on linux 4.15.0-041500rc7-generic #201801072330
Get your distro to ship an update to /usr/include/linux (kernel-headers) that contains the flag. Your kernel supports it, but your toolchain doesn't until you get an include file that includes the update for MAP_SYNC
Also, how do I make mmap support map size of 2GB or larger, currently the call to mmap fails with mapsize of 2GB.
What error code does it fail with? _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
participants (2)
-
David Frank -
valdis.kletnieks＠vt.edu