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Howlett" , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple Subject: Re: [PATCH mm-unstable v1 1/3] mm/ksm: export ksm_is_running() to check KSM merge state Message-ID: References: <20260609114619.144416-1-npache@redhat.com> <20260609114619.144416-2-npache@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260609114619.144416-2-npache@redhat.com> X-Rspamd-Queue-Id: 46C3380015 X-Stat-Signature: i9madx1c7kn1uyemfht7zpawuybj7g6b X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1781014394-665652 X-HE-Meta: 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 vJl9RSdh TTfSvokMmssVq7qFwXN5cpG2IgZd6U6yFUZVu57FxvxaF/B0Ddj/adPd8D30xcGr3rywOe5BV9OJsCCz0w59Q1CJMSXeIA+C7DBsh8YvBga5UgBQu/QB+NC2TKaMumc013sc6vzX02Tm8fmEPfLOH/pmj34/xrA7RBYNv8ks1ouocvC8H5xTPNji2Su2WQreRSOksQ8sdx24T0Ixo2wQEdXerjl2eD+smZgCTCQNmqex2MCLsrczxgohslDhLo7K4LUcAH2gQryyr+S3b8Xl3CF/c6eZtO8nuTmOjYk1jPdP9fCz1yY7CBf/vOWBRksDkhbl5KEz4x98fTbmxGhXuGuscYgbiYkofB9yraJmSC8XaDkVx2/nbvuSdS0OBQnh5YFCVTAQGHfLrSUI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jun 09, 2026 at 05:46:13AM -0600, Nico Pache wrote: > Add ksm_is_running() which returns true when KSM is actively merging > (ksm_run & KSM_RUN_MERGE). > > This will be used by try_to_map_unused_to_zeropage() to skip zero-page > remapping in VM_MERGEABLE VMAs when KSM is active. > > Signed-off-by: Nico Pache > --- > include/linux/ksm.h | 6 ++++++ > mm/ksm.c | 6 ++++++ > 2 files changed, 12 insertions(+) > > diff --git a/include/linux/ksm.h b/include/linux/ksm.h > index d39d0d5483a2..c1048b690a92 100644 > --- a/include/linux/ksm.h > +++ b/include/linux/ksm.h > @@ -17,6 +17,7 @@ > #ifdef CONFIG_KSM > int ksm_madvise(struct vm_area_struct *vma, unsigned long start, > unsigned long end, int advice, vm_flags_t *vm_flags); > +bool ksm_is_running(void); > vma_flags_t ksm_vma_flags(struct mm_struct *mm, const struct file *file, > vma_flags_t vma_flags); > int ksm_enable_merge_any(struct mm_struct *mm); > @@ -144,6 +145,11 @@ static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start, > return 0; > } > > +static inline bool ksm_is_running(void) > +{ > + return false; > +} > + > static inline struct folio *ksm_might_need_to_copy(struct folio *folio, > struct vm_area_struct *vma, unsigned long addr) > { > diff --git a/mm/ksm.c b/mm/ksm.c > index 7d5b76478f0b..edc2b961ff59 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -3015,6 +3015,12 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, > } > EXPORT_SYMBOL_GPL(ksm_madvise); > > +bool ksm_is_running(void) > +{ > + return ksm_run & KSM_RUN_MERGE; > +} > +EXPORT_SYMBOL_GPL(ksm_is_running); Why are we exporting this? What modules need this? We should never export unless we have a very specific reason to. > + > int __ksm_enter(struct mm_struct *mm) > { > struct ksm_mm_slot *mm_slot; > -- > 2.54.0 >