kernel June 2015

kernel@lists.fedoraproject.org

12 participants
13 discussions

Re: sizeof - kernel modules
by drago01 16 Jun '15

16 Jun '15

On Mon, Jun 15, 2015 at 7:38 PM, poma <pomidorabelisima(a)gmail.com> wrote: > > # du -hs /lib/modules/4.0.5-300.fc22.i686/ | awk '{print $1}' > 42M > > kernel-modules-4.0.5-300.fc22.i686.rpm ... 17M > > http://dl.fedoraproject.org/pub/fedora/linux/updates/testing/22/i386/k/ > ~~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~ ~~~~~~~ ~~~~~~ ~~~~~ ~~~~ ~~~ > > # du -hs /lib/modules/4.1.0-0.rc7.git0.1.fc23.x86_64/ | awk '{print $1}' > 53M > > kernel-modules-4.1.0-0.rc7.git0.1.fc23.x86_64.rpm ... 18M > > https://kojipkgs.fedoraproject.org/packages/kernel/4.1.0/0.rc7.git0.1.fc23/… > ~~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~ ~~~~~~~ ~~~~~~ ~~~~~ ~~~~ ~~~ ~~ ~ ~~ ~~~ > > # du -hs /lib/modules/4.1.0-0.rc7.git1.1.fc23.x86_64/ | awk '{print $1}' > 439M > > kernel-modules-4.1.0-0.rc7.git1.1.fc23.x86_64.rpm ... 218M > > http://dl.fedoraproject.org/pub/fedora/linux/development/rawhide/x86_64/os/… > ~~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~ ~~~~~~~ ~~~~~~ ~~~~~ ~~~~ ~~~ ~~ ~ ~~ ~~~ ~~~~ > > # du -hs /lib/modules/4.1.0-0.rc8.git0.1.fc23.x86_64/ | awk '{print $1}' > 438M > > kernel-modules-4.1.0-0.rc8.git0.1.fc23.x86_64.rpm ... 218M > > https://kojipkgs.fedoraproject.org/work/tasks/9420/10059420/ > ~~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~ ~~~~~~~ ~~~~~~ ~~~~~ > > > 218 ÷ 18 = 12.111111111 > 439 ÷ 53 = 8.283018868 > >>= 4.1.0-0.rc7.git1.1 cca. 10 x sizeof Those are debug builds.

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Re: kernel 4.1-rc7 deadlock
by Josh Boyer 15 Jun '15

15 Jun '15

On Mon, Jun 15, 2015 at 5:58 AM, Morten Stevens <mstevens(a)fedoraproject.org> wrote: > Hi Josh, > > Could you please add this patch to the 4.1-rc8 kernel for rawhide? > > https://lkml.org/lkml/2015/6/14/169 Done. I'd been watching that thread as well. As an aside, it is better to send such requests to the Fedora kernel list (CC'd now.) That way everyone sees it and it doesn't get lost in someone's inbox. josh > mm: shmem_zero_setup skip security check and lockdep conflict with XFS > > It appears that, at some point last year, XFS made directory handling > changes which bring it into lockdep conflict with shmem_zero_setup(): > it is surprising that mmap() can clone an inode while holding mmap_sem, > but that has been so for many years. > > Since those few lockdep traces that I've seen all implicated selinux, > I'm hoping that we can use the __shmem_file_setup(,,,S_PRIVATE) which > v3.13's commit c7277090927a ("security: shmem: implement kernel private > shmem inodes") introduced to avoid LSM checks on kernel-internal inodes: > the mmap("/dev/zero") cloned inode is indeed a kernel-internal detail. > > This also covers the !CONFIG_SHMEM use of ramfs to support /dev/zero > (and MAP_SHARED|MAP_ANONYMOUS). I thought there were also drivers > which cloned inode in mmap(), but if so, I cannot locate them now. > Reported-and-tested-by: Prarit Bhargava <prarit(a)redhat.com> > Reported-by: Daniel Wagner <wagi(a)monom.org> > Reported-by: Morten Stevens <mstevens(a)fedoraproject.org> > Signed-off-by: Hugh Dickins <hughd(a)google.com> > --- > mm/shmem.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > --- 4.1-rc7/mm/shmem.c 2015-04-26 19:16:31.352191298 -0700 > +++ linux/mm/shmem.c 2015-06-14 09:26:49.461120166 -0700 > @@ -3401,7 +3401,13 @@ int shmem_zero_setup(struct vm_area_stru > struct file *file; > loff_t size = vma->vm_end - vma->vm_start; > > - file = shmem_file_setup("dev/zero", size, vma->vm_flags); > + /* > + * Cloning a new file under mmap_sem leads to a lock ordering > conflict > + * between XFS directory reading and selinux: since this file is > only > + * accessible to the user through its mapping, use S_PRIVATE flag to > + * bypass file security, in the same way as > shmem_kernel_file_setup(). > + */ > + file = __shmem_file_setup("dev/zero", size, vma->vm_flags, > S_PRIVATE); > if (IS_ERR(file)) > return PTR_ERR(file); > > > Thank you, > > Best regards, > > Morten

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fedora 14 kernel performance with ip forwarding workload
by Jesse Brandeburg 04 Jun '15

04 Jun '15

The other day I was running the stock fedora kernel on my ip forwarding setup, to see what the performance was, and the performance wasn't very good. system is S5520HC dual socket 2.93GHz Xeon 5570 (Nehalem) with 3 quad port 82580 adapters (12 ports). Traffic is bidirectional 64 byte packets being forwarded and received on each port, basically port to port routing. I am only using 12 flows currently. The driver is igb, and I am using an affinity script that lines up each pair of ports that are forwarding traffic into optimal configurations for cache locality. I am also disabling remote_node_defrag_ratio to stop cross node traffic. With the fedora default kernel from F14 it appears that CONFIG_NETFILTER=y means that I cannot unload all of netfilter even if I stop iptables service. perf showed netfilter being prominent, and removing it gives me much higher throughput. Is there a reason CONFIG_NETFILTER=y ? Isn't it a good thing to be able to disable netfilter if you want to? Jesse

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kernel June 2015