From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5925236A9F; Wed, 2 Jul 2025 23:51:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751500301; cv=none; b=FWmWunhh3BFsHak+Q5f5Vl1/7gNe6U6W2GQ3lObC9v9jv81Pi8ELrzpWGmTrrhqylHkCmM8S+2Iun4Ds12czG8H8V8HC9GRqFA41F6zCamqfE530UcXNch58cQuMVwG4HcPbKJbWmhFDkUBA044SRQ5X6VLEUbDZ5sVN1fzAfzo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751500301; c=relaxed/simple; bh=phXhRif4QEx6/qVW8NoYnau8fG9rcxcu4dhrIomKfiw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=PF4eBI5flIj1AU3qPqlzRoUzKLRCOOdk1lLShoZJ4FhKsQ+5mgfNCxH7RVhwSrMavyio7pWUoKxF5In6fTHFlqzwwqffv8rOhsTkBIlIwqG+jMpbqCLvp32ITHB0kLuw2ezPcgMEGkjp0mvuz+vpuXwU+r9STAokJbVQzIr1Kd0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OmRc81Fz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OmRc81Fz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20B92C4CEE7; Wed, 2 Jul 2025 23:51:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751500300; bh=phXhRif4QEx6/qVW8NoYnau8fG9rcxcu4dhrIomKfiw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OmRc81FzvYLXerzuw68/k+ABrjneyRG/WsseBhXMWJhEDHyHQw+IKVDOjr+DX9BJb lyMAIFg4uFGrmEthFp/rur4P5M9TG0RQI833SezpOkbFCQ/FF5Bk+J1vhPKgpyzKNj ajaHWw0eJlbbWcxR81fbnBZdq2WbgEHKP5/ekdSsY9Aje5hS6J0RpieeCq8G89lU/i /uncvHSJVB0N33IIJNJNUQojeBCMC58ffRg+HQzNMlm1YjsDk4uF5DYpNSnbbCLYOi zQRb+JFbNViTjD57YQZYCnH4ael3xCcp2Hl9fytDNJKaqg2NqDKis6W6ydUU4ZAqAx uMG912n8ySdpA== From: SeongJae Park To: Bijan Tabatabai Cc: SeongJae Park , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, akpm@linux-foundation.org, corbet@lwn.net, joshua.hahnjy@gmail.com, bijantabatab@micron.com, venkataravis@micron.com, emirakhur@micron.com, ajayjoshi@micron.com, vtavarespetr@micron.com, Ravi Shankar Jonnalagadda Subject: Re: [RFC PATCH v3 09/13] mm/damon/vaddr: Add vaddr versions of migrate_{hot,cold} Date: Wed, 2 Jul 2025 16:51:38 -0700 Message-Id: <20250702235138.56720-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250702201337.5780-10-bijan311@gmail.com> References: Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 2 Jul 2025 15:13:32 -0500 Bijan Tabatabai wrote: > From: Bijan Tabatabai > > migrate_{hot,cold} are paddr schemes that are used to migrate hot/cold > data to a specified node. However, these schemes are only available when > doing physical address monitoring. This patch adds an implementation for > them virtual address monitoring as well. > > Co-developed-by: Ravi Shankar Jonnalagadda > Signed-off-by: Ravi Shankar Jonnalagadda > Signed-off-by: Bijan Tabatabai > --- > mm/damon/vaddr.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 102 insertions(+) > > diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c > index 46554e49a478..5cdfdc47c5ff 100644 > --- a/mm/damon/vaddr.c > +++ b/mm/damon/vaddr.c > @@ -15,6 +15,7 @@ > #include > #include > > +#include "../internal.h" > #include "ops-common.h" > > #ifdef CONFIG_DAMON_VADDR_KUNIT_TEST > @@ -610,6 +611,65 @@ static unsigned int damon_va_check_accesses(struct damon_ctx *ctx) > return max_nr_accesses; > } > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +static int damos_va_migrate_pmd_entry(pmd_t *pmd, unsigned long addr, > + unsigned long next, struct mm_walk *walk) I'd suggest to put CONFIG_TRANSPARENT_HUGEPAGE check into the body of this function and handle both pmd and pte here, consistent to damon_young_pmd_entry(). > +{ > + struct list_head *migration_list = walk->private; > + struct folio *folio; > + spinlock_t *ptl; > + pmd_t pmde; > + > + ptl = pmd_lock(walk->mm, pmd); > + pmde = pmdp_get(pmd); > + > + if (!pmd_present(pmde) || !pmd_trans_huge(pmde)) > + goto unlock; > + > + folio = damon_get_folio(pmd_pfn(pmde)); > + if (!folio) > + goto unlock; > + > + if (!folio_isolate_lru(folio)) > + goto put_folio; > + > + list_add(&folio->lru, migration_list); > + > +put_folio: > + folio_put(folio); > +unlock: > + spin_unlock(ptl); > + return 0; > +} > +#else > +#define damos_va_migrate_pmd_entry NULL > +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ > + > +static int damos_va_migrate_pte_entry(pte_t *pte, unsigned long addr, > + unsigned long enxt, struct mm_walk *walk) Nit. s/enxt/next/ ? > +{ > + struct list_head *migration_list = walk->private; > + struct folio *folio; > + pte_t ptent; > + > + ptent = ptep_get(pte); > + if (pte_none(*pte) || !pte_present(*pte)) > + return 0; Shouldn't we use cached pte value (ptent) instad of *pte? I'd suggest merging this into damos_va_migrate_pmd_entry() consistent to damon_young_pmd_entry(). > + > + folio = damon_get_folio(pte_pfn(ptent)); > + if (!folio) > + return 0; > + > + if (!folio_isolate_lru(folio)) > + goto out; > + > + list_add(&folio->lru, migration_list); > + > +out: > + folio_put(folio); > + return 0; > +} > + > /* > * Functions for the target validity check and cleanup > */ > @@ -653,6 +713,41 @@ static unsigned long damos_madvise(struct damon_target *target, > } > #endif /* CONFIG_ADVISE_SYSCALLS */ > > +static unsigned long damos_va_migrate(struct damon_target *target, > + struct damon_region *r, struct damos *s, > + unsigned long *sz_filter_passed) > +{ > + LIST_HEAD(folio_list); > + struct task_struct *task; > + struct mm_struct *mm; > + unsigned long applied = 0; > + struct mm_walk_ops walk_ops = { > + .pmd_entry = damos_va_migrate_pmd_entry, > + .pte_entry = damos_va_migrate_pte_entry, > + .walk_lock = PGWALK_RDLOCK, > + }; > + > + task = damon_get_task_struct(target); > + if (!task) > + return 0; > + > + mm = damon_get_mm(target); > + if (!mm) > + goto put_task; > + > + mmap_read_lock(mm); > + walk_page_range(mm, r->ar.start, r->ar.end, &walk_ops, &folio_list); > + mmap_read_unlock(mm); > + mmput(mm); > + > + applied = damon_migrate_pages(&folio_list, s->target_nid); > + cond_resched(); > + > +put_task: > + put_task_struct(task); Seems task is not being used in real, so this variable and the related code in this function can be removed? Or, am I missing something? > + return applied * PAGE_SIZE; > +} > + > static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx, > struct damon_target *t, struct damon_region *r, > struct damos *scheme, unsigned long *sz_filter_passed) > @@ -675,6 +770,9 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx, > case DAMOS_NOHUGEPAGE: > madv_action = MADV_NOHUGEPAGE; > break; > + case DAMOS_MIGRATE_HOT: > + case DAMOS_MIGRATE_COLD: > + return damos_va_migrate(t, r, scheme, sz_filter_passed); > case DAMOS_STAT: > return 0; > default: > @@ -695,6 +793,10 @@ static int damon_va_scheme_score(struct damon_ctx *context, > switch (scheme->action) { > case DAMOS_PAGEOUT: > return damon_cold_score(context, r, scheme); > + case DAMOS_MIGRATE_HOT: > + return damon_hot_score(context, r, scheme); > + case DAMOS_MIGRATE_COLD: > + return damon_cold_score(context, r, scheme); > default: > break; > } > -- > 2.43.5 Thanks, SJ