* + mm-huge_memory-refactor-enabled_store-with-change_enabled.patch added to mm-new branch
@ 2026-03-11 17:22 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2026-03-11 17:22 UTC (permalink / raw)
To: mm-commits, ziy, usamaarif642, surenb, ryan.roberts, rppt,
richard.weiyang, npache, mhocko, ljs, liam.howlett, lance.yang,
jackmanb, hannes, dev.jain, david, baolin.wang, baohua, leitao,
akpm
The patch titled
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
has been added to the -mm mm-new branch. Its filename is
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will later appear in the mm-new branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews. Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.
The mm-new branch of mm.git is not included in linux-next
If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next
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: Breno Leitao <leitao@debian.org>
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
Date: Wed, 11 Mar 2026 03:17:49 -0700
Refactor enabled_store() to use a new change_enabled() helper. Introduce
a separate enum global_enabled_mode and global_enabled_mode_strings[],
mirroring the anon_enabled_mode pattern from the previous commit.
A separate enum is necessary because the global THP setting does not
support "inherit", only "always", "madvise", and "never". Reusing
anon_enabled_mode would leave a NULL gap in the string array, causing
sysfs_match_string() to stop early and fail to match entries after the
gap.
The helper uses the same loop pattern as set_anon_enabled_mode(),
iterating over an array of flag bit positions and using
__test_and_set_bit()/__test_and_clear_bit() to track whether the state
actually changed.
Link: https://lkml.kernel.org/r/20260311-thp_logs-v6-3-421e30d881e0@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 63 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 15 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-refactor-enabled_store-with-change_enabled
+++ a/mm/huge_memory.c
@@ -330,30 +330,63 @@ static const char * const anon_enabled_m
[ANON_ENABLED_NEVER] = "never",
};
+enum global_enabled_mode {
+ GLOBAL_ENABLED_ALWAYS = 0,
+ GLOBAL_ENABLED_MADVISE = 1,
+ GLOBAL_ENABLED_NEVER = 2,
+};
+
+static const char * const global_enabled_mode_strings[] = {
+ [GLOBAL_ENABLED_ALWAYS] = "always",
+ [GLOBAL_ENABLED_MADVISE] = "madvise",
+ [GLOBAL_ENABLED_NEVER] = "never",
+};
+
+static bool set_global_enabled_mode(enum global_enabled_mode mode)
+{
+ static const unsigned long thp_flags[] = {
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ };
+ enum global_enabled_mode m;
+ bool changed = false;
+
+ for (m = 0; m < ARRAY_SIZE(thp_flags); m++) {
+ if (m == mode)
+ changed |= !__test_and_set_bit(thp_flags[m],
+ &transparent_hugepage_flags);
+ else
+ changed |= __test_and_clear_bit(thp_flags[m],
+ &transparent_hugepage_flags);
+ }
+
+ return changed;
+}
+
static ssize_t enabled_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
- ssize_t ret = count;
+ int mode;
- if (sysfs_streq(buf, "always")) {
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "madvise")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "never")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else
- ret = -EINVAL;
+ mode = sysfs_match_string(global_enabled_mode_strings, buf);
+ if (mode < 0)
+ return -EINVAL;
- if (ret > 0) {
+ if (set_global_enabled_mode(mode)) {
int err = start_stop_khugepaged();
+
if (err)
- ret = err;
+ return err;
+ } else {
+ /*
+ * Recalculate watermarks even when the mode didn't
+ * change, as the previous code always called
+ * start_stop_khugepaged() which does this internally.
+ */
+ set_recommended_min_free_kbytes();
}
- return ret;
+ return count;
}
static struct kobj_attribute enabled_attr = __ATTR_RW(enabled);
_
Patches currently in -mm which might be from leitao@debian.org are
selftests-mm-add-thp-sysfs-interface-test.patch
mm-khugepaged-export-set_recommended_min_free_kbytes.patch
mm-huge_memory-refactor-anon_enabled_store-with-change_anon_orders.patch
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
mm-ratelimit-min_free_kbytes-adjustment-messages.patch
^ permalink raw reply [flat|nested] 4+ messages in thread* + mm-huge_memory-refactor-enabled_store-with-change_enabled.patch added to mm-new branch
@ 2026-03-10 18:30 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2026-03-10 18:30 UTC (permalink / raw)
To: mm-commits, ziy, vbabka, usamaarif642, surenb, ryan.roberts, rppt,
npache, mhocko, ljs, liam.howlett, lance.yang, jackmanb, hannes,
dev.jain, david, baolin.wang, baohua, leitao, akpm
The patch titled
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
has been added to the -mm mm-new branch. Its filename is
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will later appear in the mm-new branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews. Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.
The mm-new branch of mm.git is not included in linux-next
If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next
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: Breno Leitao <leitao@debian.org>
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
Date: Tue, 10 Mar 2026 10:57:09 -0700
Refactor enabled_store() to use a new change_enabled() helper. Introduce
a separate enum global_enabled_mode and global_enabled_mode_strings[],
mirroring the anon_enabled_mode pattern from the previous commit.
A separate enum is necessary because the global THP setting does not
support "inherit", only "always", "madvise", and "never". Reusing
anon_enabled_mode would leave a NULL gap in the string array, causing
sysfs_match_string() to stop early and fail to match entries after the
gap.
The helper uses the same loop pattern as set_anon_enabled_mode(),
iterating over an array of flag bit positions and using
__test_and_set_bit()/__test_and_clear_bit() to track whether the state
actually changed.
Link: https://lkml.kernel.org/r/20260310-thp_logs-v5-3-686099175bf6@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 63 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 15 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-refactor-enabled_store-with-change_enabled
+++ a/mm/huge_memory.c
@@ -330,30 +330,63 @@ static const char * const anon_enabled_m
[ANON_ENABLED_NEVER] = "never",
};
+enum global_enabled_mode {
+ GLOBAL_ENABLED_ALWAYS = 0,
+ GLOBAL_ENABLED_MADVISE = 1,
+ GLOBAL_ENABLED_NEVER = 2,
+};
+
+static const char * const global_enabled_mode_strings[] = {
+ [GLOBAL_ENABLED_ALWAYS] = "always",
+ [GLOBAL_ENABLED_MADVISE] = "madvise",
+ [GLOBAL_ENABLED_NEVER] = "never",
+};
+
+static bool set_global_enabled_mode(enum global_enabled_mode mode)
+{
+ static const unsigned long thp_flags[] = {
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ };
+ enum global_enabled_mode m;
+ bool changed = false;
+
+ for (m = 0; m < ARRAY_SIZE(thp_flags); m++) {
+ if (m == mode)
+ changed |= !__test_and_set_bit(thp_flags[m],
+ &transparent_hugepage_flags);
+ else
+ changed |= __test_and_clear_bit(thp_flags[m],
+ &transparent_hugepage_flags);
+ }
+
+ return changed;
+}
+
static ssize_t enabled_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
- ssize_t ret = count;
+ int mode;
- if (sysfs_streq(buf, "always")) {
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "madvise")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "never")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else
- ret = -EINVAL;
+ mode = sysfs_match_string(global_enabled_mode_strings, buf);
+ if (mode < 0)
+ return -EINVAL;
- if (ret > 0) {
+ if (set_global_enabled_mode(mode)) {
int err = start_stop_khugepaged();
+
if (err)
- ret = err;
+ return err;
+ } else {
+ /*
+ * Recalculate watermarks even when the mode didn't
+ * change, as the previous code always called
+ * start_stop_khugepaged() which does this internally.
+ */
+ set_recommended_min_free_kbytes();
}
- return ret;
+ return count;
}
static struct kobj_attribute enabled_attr = __ATTR_RW(enabled);
_
Patches currently in -mm which might be from leitao@debian.org are
selftests-mm-add-thp-sysfs-interface-test.patch
mm-khugepaged-export-set_recommended_min_free_kbytes.patch
mm-huge_memory-refactor-anon_enabled_store-with-change_anon_orders.patch
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
mm-ratelimit-min_free_kbytes-adjustment-messages.patch
^ permalink raw reply [flat|nested] 4+ messages in thread* + mm-huge_memory-refactor-enabled_store-with-change_enabled.patch added to mm-new branch
@ 2026-03-09 20:04 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2026-03-09 20:04 UTC (permalink / raw)
To: mm-commits, ziy, usamaarif642, surenb, ryan.roberts, rppt, npache,
mhocko, ljs, liam.howlett, lance.yang, jackmanb, hannes, dev.jain,
david, baolin.wang, baohua, leitao, akpm
The patch titled
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
has been added to the -mm mm-new branch. Its filename is
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will later appear in the mm-new branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews. Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.
The mm-new branch of mm.git is not included in linux-next
If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next
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: Breno Leitao <leitao@debian.org>
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
Date: Mon, 09 Mar 2026 04:07:32 -0700
Refactor enabled_store() to use a new change_enabled() helper. Introduce
a separate enum global_enabled_mode and global_enabled_mode_strings[],
mirroring the anon_enabled_mode pattern from the previous commit.
A separate enum is necessary because the global THP setting does not
support "inherit", only "always", "madvise", and "never". Reusing
anon_enabled_mode would leave a NULL gap in the string array, causing
sysfs_match_string() to stop early and fail to match entries after the
gap.
The helper uses the same loop pattern as change_anon_orders(), iterating
over an array of flag bit positions and using
test_and_set_bit()/test_and_clear_bit() to track whether the state
actually changed.
Link: https://lkml.kernel.org/r/20260309-thp_logs-v4-3-926b9840083e@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 63 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 15 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-refactor-enabled_store-with-change_enabled
+++ a/mm/huge_memory.c
@@ -330,30 +330,63 @@ static const char * const anon_enabled_m
[ANON_ENABLED_NEVER] = "never",
};
+enum global_enabled_mode {
+ GLOBAL_ENABLED_ALWAYS = 0,
+ GLOBAL_ENABLED_MADVISE = 1,
+ GLOBAL_ENABLED_NEVER = 2,
+};
+
+static const char * const global_enabled_mode_strings[] = {
+ [GLOBAL_ENABLED_ALWAYS] = "always",
+ [GLOBAL_ENABLED_MADVISE] = "madvise",
+ [GLOBAL_ENABLED_NEVER] = "never",
+};
+
+static bool change_enabled(enum global_enabled_mode mode)
+{
+ static const unsigned long thp_flags[] = {
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ };
+ enum global_enabled_mode m;
+ bool changed = false;
+
+ for (m = 0; m < ARRAY_SIZE(thp_flags); m++) {
+ if (m == mode)
+ changed |= !test_and_set_bit(thp_flags[m],
+ &transparent_hugepage_flags);
+ else
+ changed |= test_and_clear_bit(thp_flags[m],
+ &transparent_hugepage_flags);
+ }
+
+ return changed;
+}
+
static ssize_t enabled_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
- ssize_t ret = count;
+ int mode;
- if (sysfs_streq(buf, "always")) {
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "madvise")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "never")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else
- ret = -EINVAL;
+ mode = sysfs_match_string(global_enabled_mode_strings, buf);
+ if (mode < 0)
+ return -EINVAL;
- if (ret > 0) {
+ if (change_enabled(mode)) {
int err = start_stop_khugepaged();
+
if (err)
- ret = err;
+ return err;
+ } else {
+ /*
+ * Recalculate watermarks even when the mode didn't
+ * change, as the previous code always called
+ * start_stop_khugepaged() which does this internally.
+ */
+ set_recommended_min_free_kbytes();
}
- return ret;
+ return count;
}
static struct kobj_attribute enabled_attr = __ATTR_RW(enabled);
_
Patches currently in -mm which might be from leitao@debian.org are
selftests-mm-add-thp-sysfs-interface-test.patch
mm-khugepaged-export-set_recommended_min_free_kbytes.patch
mm-huge_memory-refactor-anon_enabled_store-with-change_anon_orders.patch
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
mm-ratelimit-min_free_kbytes-adjustment-messages.patch
^ permalink raw reply [flat|nested] 4+ messages in thread* + mm-huge_memory-refactor-enabled_store-with-change_enabled.patch added to mm-new branch
@ 2026-03-08 21:06 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2026-03-08 21:06 UTC (permalink / raw)
To: mm-commits, ziy, vbabka, usamaarif642, surenb, ryan.roberts, rppt,
npache, mhocko, ljs, liam.howlett, lance.yang, jackmanb, hannes,
dev.jain, david, baolin.wang, baohua, leitao, akpm
The patch titled
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
has been added to the -mm mm-new branch. Its filename is
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
This patch will later appear in the mm-new branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews. Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.
The mm-new branch of mm.git is not included in linux-next
If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next
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: Breno Leitao <leitao@debian.org>
Subject: mm: huge_memory: refactor enabled_store() with change_enabled()
Date: Sat, 07 Mar 2026 08:08:07 -0800
Refactor enabled_store() to use a new change_enabled() helper. Introduce
a separate enum global_enabled_mode and global_enabled_mode_strings[],
mirroring the anon_enabled_mode pattern from the previous commit.
A separate enum is necessary because the global THP setting does not
support "inherit", only "always", "madvise", and "never". Reusing
anon_enabled_mode would leave a NULL gap in the string array, causing
sysfs_match_string() to stop early and fail to match entries after the
gap.
The helper uses the same loop pattern as change_anon_orders(), iterating
over an array of flag bit positions and using
test_and_set_bit()/test_and_clear_bit() to track whether the state
actually changed.
Link: https://lkml.kernel.org/r/20260307-thp_logs-v3-3-a45d2c8f3685@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 63 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 15 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-refactor-enabled_store-with-change_enabled
+++ a/mm/huge_memory.c
@@ -330,30 +330,63 @@ static const char * const anon_enabled_m
[ANON_ENABLED_NEVER] = "never",
};
+enum global_enabled_mode {
+ GLOBAL_ENABLED_ALWAYS,
+ GLOBAL_ENABLED_MADVISE,
+ GLOBAL_ENABLED_NEVER,
+};
+
+static const char * const global_enabled_mode_strings[] = {
+ [GLOBAL_ENABLED_ALWAYS] = "always",
+ [GLOBAL_ENABLED_MADVISE] = "madvise",
+ [GLOBAL_ENABLED_NEVER] = "never",
+};
+
+static bool change_enabled(enum global_enabled_mode mode)
+{
+ static const unsigned long thp_flags[] = {
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ };
+ bool changed = false;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(thp_flags); i++) {
+ if (i == mode)
+ changed |= !test_and_set_bit(thp_flags[i],
+ &transparent_hugepage_flags);
+ else
+ changed |= test_and_clear_bit(thp_flags[i],
+ &transparent_hugepage_flags);
+ }
+
+ return changed;
+}
+
static ssize_t enabled_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
- ssize_t ret = count;
+ int mode;
- if (sysfs_streq(buf, "always")) {
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "madvise")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else if (sysfs_streq(buf, "never")) {
- clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags);
- clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags);
- } else
- ret = -EINVAL;
+ mode = sysfs_match_string(global_enabled_mode_strings, buf);
+ if (mode < 0)
+ return -EINVAL;
- if (ret > 0) {
+ if (change_enabled(mode)) {
int err = start_stop_khugepaged();
+
if (err)
- ret = err;
+ return err;
+ } else {
+ /*
+ * Recalculate watermarks even when the mode didn't
+ * change, as the previous code always called
+ * start_stop_khugepaged() which does this internally.
+ */
+ set_recommended_min_free_kbytes();
}
- return ret;
+ return count;
}
static struct kobj_attribute enabled_attr = __ATTR_RW(enabled);
_
Patches currently in -mm which might be from leitao@debian.org are
mm-khugepaged-export-set_recommended_min_free_kbytes.patch
mm-huge_memory-refactor-anon_enabled_store-with-change_anon_orders.patch
mm-huge_memory-refactor-enabled_store-with-change_enabled.patch
mm-ratelimit-min_free_kbytes-adjustment-messages.patch
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-03-11 17:22 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2026-03-11 17:22 + mm-huge_memory-refactor-enabled_store-with-change_enabled.patch added to mm-new branch Andrew Morton
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2026-03-10 18:30 Andrew Morton
2026-03-09 20:04 Andrew Morton
2026-03-08 21:06 Andrew Morton
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