On 6/3/20 8:50 AM, Gavin Guo wrote: > There is no way to set up the defrag options in boot time. And it's > useful to set it up by default instead of making it work by a > systemd/upstart service or put the command to set up defrag inside > /etc/rc.local. > > Signed-off-by: Gavin Guo <gavin.guo@xxxxxxxxxxxxx> Well, maybe isntead of adding these handlers, we could extend the new boot parameter sysctl support (handling procfs /proc/sys/) to sysfs (/sys) as well, as Eric already suggested? [1] [1] https://lore.kernel.org/linux-api/87bloj2skm.fsf@xxxxxxxxxxxxxxxxxxxxx/ > --- > .../admin-guide/kernel-parameters.txt | 18 ++++++++ > mm/huge_memory.c | 43 +++++++++++++++++++ > mm/khugepaged.c | 21 +++++++++ > 3 files changed, 82 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 6253849afac2..a9fd020d78db 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2149,6 +2149,16 @@ > kgdbwait [KGDB] Stop kernel execution and enter the > kernel debugger at the earliest opportunity. > > + khugepaged_defrag= > + [KNL] > + Format: { "0" | "1" } > + 0 - disable the defrag > + 1 - enable the defrag > + Control the defrag efforts when generating the > + transparent hugepages through khugepaged. > + See Documentation/admin-guide/mm/transhuge.rst > + for more details. > + > kmac= [MIPS] korina ethernet MAC address. > Configure the RouterBoard 532 series on-chip > Ethernet adapter MAC address. > @@ -5146,6 +5156,14 @@ > See Documentation/admin-guide/mm/transhuge.rst > for more details. > > + transparent_hugepage_defrag= > + [KNL] > + Format: [always|defer|defer+madvise|madvise|never] > + Control the defrag efforts when generating the > + transparent hugepages. > + See Documentation/admin-guide/mm/transhuge.rst > + for more details. > + > tsc= Disable clocksource stability checks for TSC. > Format: <string> > [x86] reliable: mark tsc clocksource as reliable, this > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 8091b780cd7a..86b20a3a1aac 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -481,6 +481,49 @@ static int __init setup_transparent_hugepage(char *str) > } > __setup("transparent_hugepage=", setup_transparent_hugepage); > > +static int __init setup_transparent_hugepage_defrag(char *str) > +{ > + int ret = 0; > + if (!str) > + goto out; > + if (!strcmp(str, "always")) { > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); > + set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); > + ret = 1; > + } else if (!strcmp(str, "defer+madvise")) { > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); > + set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); > + ret = 1; > + } else if (!strcmp(str, "defer")) { > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); > + set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); > + ret = 1; > + } else if (!strcmp(str, "madvise")) { > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); > + set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); > + ret = 1; > + } else if (!strcmp(str, "never")) { > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); > + ret = 1; > + } > +out: > + if (!ret) > + pr_warn("transparent_hugepage_defrag= cannot parse, ignored\n"); > + return ret; > +} > +__setup("transparent_hugepage_defrag=", setup_transparent_hugepage_defrag); > + > pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) > { > if (likely(vma->vm_flags & VM_WRITE)) > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index b043c40a21d4..39bbf2107a23 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -394,6 +394,27 @@ int __init khugepaged_init(void) > return 0; > } > > +static int __init setup_khugepaged_defrag(char *str) > +{ > + int ret = 0; > + if (!str) > + goto out; > + if (!strcmp(str, "0")) { > + clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG, > + &transparent_hugepage_flags); > + ret = 1; > + } else if (!strcmp(str, "1")) { > + set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG, > + &transparent_hugepage_flags); > + ret = 1; > + } > +out: > + if (!ret) > + pr_warn("khugepaged_defrag= cannot parse, ignored\n"); > + return ret; > +} > +__setup("khugepaged_defrag=", setup_khugepaged_defrag); > + > void __init khugepaged_destroy(void) > { > kmem_cache_destroy(mm_slot_cache); >
