From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792820110; b=StR5tQTdlj8IkBMcpdbmOUoQf/e/xiMnGIRz+YnXF5MTNVvlH7CDNAauJHpCqhT6nDzi KEJQPM52fP3LhY7qrOKH0kVu+dyOiZRUxnAGa8e8yegP36OAMhNLZhSu0OhHTztc2q/XJ 1HXrnvftaKyjzPfzzqMweI7tOZcGxCTREHNP0y2tx/fZkD8oMMMWLGEoHYS0xg5ft15mv 3NLa7qNIhaUG5u9391TZiUoeS07NTLHz7UE7pU6aJ/Szu7HgeJgte/ei08lN9DsDaHina 3avre12gCoSm0Uqvg+zjJvBAEj5H80VakphP2uEytxA2rwrOjtZvozfYk4Qh6aQsiFA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792820110; h=Received:DKIM-Signature:Date:To:From:Subject:Message-Id; bh=qgbzmH5BLez84vXWBuY4DmS0hOrRqlGiPhvAlG/Z/C8=; b=vsYqLT/AW+TyuGpHRAXRj6vGWxAm+Lz0QmaZFVR/+o68gkKhYEHGSynwE1nx9TUhMA59 Kn01el659vW1kC/5PgGH/coGEweZPuHXopnoBe4uc2CR7ZwH20k/oBvlDiz+1VNmhpypu aLImArVIY0VePYXaowNSjfSEhge89FXSu+8MRjswTaGbigtGpPGeoZz5dBOhNyfUEHwDf crTTurY5lXDpbqqywJkiEp4J+dNpxPVUjf+2u9vO3yPjWDzNaeCh0rUOsJEhFJlCHjZoe DDOaYX0eaXep+312S/QzkBT8mQkJsYAcQZtcv4oBLjKduoUqpRV7w7t/F3ihGiRwzFA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=HvrvEHRe; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E7DF60A2611; Sat, 24 Oct 2026 05:35:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=HvrvEHRe Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25B991F01828; Sat, 24 Oct 2026 05:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1792820110; bh=qgbzmH5BLez84vXWBuY4DmS0hOrRqlGiPhvAlG/Z/C8=; h=Date:To:From:Subject; b=HvrvEHRe5DnD6pfBrWQNDkM+Xekwq4Mqwq2iHitBGm0zUly3UgtCWE+BGzhjGAsEb fYf19eEIm0nLHb43HpptWV+1TJ3TDQCuzOs+NziI1FCIo+8TjIZTnbTIdCqumszI8r wCpxtiGA9d7n3a0/ywoU0uheDTV0t0wvTeymKzy0= Date: Fri, 23 Oct 2026 22:35:09 -0700 To: mm-commits@vger.kernel.org,xu.xin@linux.dev,stable@vger.kernel.org,rppt@kernel.org,peterx@redhat.com,lance.yang@linux.dev,kas@kernel.org,david@kernel.org,chengming.zhou@linux.dev,samarth.colleges@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-ksm-keep-soft-dirty-when-merging-a-page.patch added to mm-unstable branch Message-Id: <20261024053510.25B991F01828@smtp.kernel.org> X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list The patch titled Subject: mm/ksm: keep soft-dirty when merging a page has been added to the -mm mm-unstable branch. Its filename is mm-ksm-keep-soft-dirty-when-merging-a-page.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ksm-keep-soft-dirty-when-merging-a-page.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Samarth Narang Subject: mm/ksm: keep soft-dirty when merging a page Date: Wed, 21 Oct 2026 11:21:57 -0700 replace_page() maps the KSM page with a PTE built from scratch, so the soft-dirty bit of the PTE it replaces is lost. A page written since "clear_refs 4" then no longer shows as soft-dirty once it is merged, and a soft-dirty based dumper treats it as unchanged. Copy the soft-dirty bit from the original PTE to the new PTE. Link: https://lore.kernel.org/20261021182157.1873726-1-samarth.colleges@gmail.com Fixes: 0f8975ec4db2 ("mm: soft-dirty bits for user memory changes tracking") Signed-off-by: Samarth Narang Signed-off-by: Andrew Morton Reviewed-by: Lance Yang Assisted-by: LLM Cc: David Hildenbrand Cc: Xu Xin Cc: Chengming Zhou Cc: Peter Xu Cc: Kiryl Shutsemau Cc: Mike Rapoport Cc: --- mm/ksm.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/ksm.c~mm-ksm-keep-soft-dirty-when-merging-a-page +++ a/mm/ksm.c @@ -1463,6 +1463,10 @@ static int replace_page(struct vm_area_s dec_mm_counter(mm, MM_ANONPAGES); } + /* Preserve soft-dirty when replacing the page. */ + if (pte_soft_dirty(orig_pte)) + newpte = pte_mksoft_dirty(newpte); + flush_cache_page(vma, addr, pte_pfn(ptep_get(ptep))); /* * No need to notify as we are replacing a read only page with another _ Patches currently in -mm which might be from samarth.colleges@gmail.com are mm-ksm-keep-soft-dirty-when-merging-a-page.patch