/proc/meminfo says VmallocUsed is 0. So where are my kernel modules stored?











up vote
1
down vote

favorite












I thought the code for kernel modules was stored in a vmalloc() allocation? (In fact I'm sure the kernel code is using vmalloc(), not kvmalloc()). So why does /proc/meminfo say I have no zero VmallocUsed ?



$ grep Vmalloc /proc/meminfo
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
$ lsmod|head
Module Size Used by
vfio_mdev 16384 0
mdev 20480 1 vfio_mdev
vfio_iommu_type1 28672 0
vfio 32768 2 vfio_mdev,vfio_iommu_type1
kvm_intel 237568 0
kvm 737280 1 kvm_intel
irqbypass 16384 1 kvm
dummy 16384 0
binfmt_misc 20480 1









share|improve this question


























    up vote
    1
    down vote

    favorite












    I thought the code for kernel modules was stored in a vmalloc() allocation? (In fact I'm sure the kernel code is using vmalloc(), not kvmalloc()). So why does /proc/meminfo say I have no zero VmallocUsed ?



    $ grep Vmalloc /proc/meminfo
    VmallocTotal: 34359738367 kB
    VmallocUsed: 0 kB
    VmallocChunk: 0 kB
    $ lsmod|head
    Module Size Used by
    vfio_mdev 16384 0
    mdev 20480 1 vfio_mdev
    vfio_iommu_type1 28672 0
    vfio 32768 2 vfio_mdev,vfio_iommu_type1
    kvm_intel 237568 0
    kvm 737280 1 kvm_intel
    irqbypass 16384 1 kvm
    dummy 16384 0
    binfmt_misc 20480 1









    share|improve this question
























      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      I thought the code for kernel modules was stored in a vmalloc() allocation? (In fact I'm sure the kernel code is using vmalloc(), not kvmalloc()). So why does /proc/meminfo say I have no zero VmallocUsed ?



      $ grep Vmalloc /proc/meminfo
      VmallocTotal: 34359738367 kB
      VmallocUsed: 0 kB
      VmallocChunk: 0 kB
      $ lsmod|head
      Module Size Used by
      vfio_mdev 16384 0
      mdev 20480 1 vfio_mdev
      vfio_iommu_type1 28672 0
      vfio 32768 2 vfio_mdev,vfio_iommu_type1
      kvm_intel 237568 0
      kvm 737280 1 kvm_intel
      irqbypass 16384 1 kvm
      dummy 16384 0
      binfmt_misc 20480 1









      share|improve this question













      I thought the code for kernel modules was stored in a vmalloc() allocation? (In fact I'm sure the kernel code is using vmalloc(), not kvmalloc()). So why does /proc/meminfo say I have no zero VmallocUsed ?



      $ grep Vmalloc /proc/meminfo
      VmallocTotal: 34359738367 kB
      VmallocUsed: 0 kB
      VmallocChunk: 0 kB
      $ lsmod|head
      Module Size Used by
      vfio_mdev 16384 0
      mdev 20480 1 vfio_mdev
      vfio_iommu_type1 28672 0
      vfio 32768 2 vfio_mdev,vfio_iommu_type1
      kvm_intel 237568 0
      kvm 737280 1 kvm_intel
      irqbypass 16384 1 kvm
      dummy 16384 0
      binfmt_misc 20480 1






      linux-kernel memory kernel-modules






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked 2 days ago









      sourcejedi

      21.9k43396




      21.9k43396






















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          2
          down vote













          The fields were zeroed in Linux 4.4, for performance reasons. Programs linked against glibc read this file when they started up, and it was causing a measurable impact.



          https://github.com/torvalds/linux/commit/a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0






          share|improve this answer





















            Your Answer








            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "106"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            convertImagesToLinks: false,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: null,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














             

            draft saved


            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f482772%2fproc-meminfo-says-vmallocused-is-0-so-where-are-my-kernel-modules-stored%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            2
            down vote













            The fields were zeroed in Linux 4.4, for performance reasons. Programs linked against glibc read this file when they started up, and it was causing a measurable impact.



            https://github.com/torvalds/linux/commit/a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0






            share|improve this answer

























              up vote
              2
              down vote













              The fields were zeroed in Linux 4.4, for performance reasons. Programs linked against glibc read this file when they started up, and it was causing a measurable impact.



              https://github.com/torvalds/linux/commit/a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0






              share|improve this answer























                up vote
                2
                down vote










                up vote
                2
                down vote









                The fields were zeroed in Linux 4.4, for performance reasons. Programs linked against glibc read this file when they started up, and it was causing a measurable impact.



                https://github.com/torvalds/linux/commit/a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0






                share|improve this answer












                The fields were zeroed in Linux 4.4, for performance reasons. Programs linked against glibc read this file when they started up, and it was causing a measurable impact.



                https://github.com/torvalds/linux/commit/a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered 2 days ago









                sourcejedi

                21.9k43396




                21.9k43396






























                     

                    draft saved


                    draft discarded



















































                     


                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f482772%2fproc-meminfo-says-vmallocused-is-0-so-where-are-my-kernel-modules-stored%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    サソリ

                    広島県道265号伴広島線

                    Accessing regular linux commands in Huawei's Dopra Linux