From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E7DEF3C3443 for ; Tue, 2 Jun 2026 22:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780439205; cv=none; b=qu3ZZAt/+HJFXzELCiuBfeexOantmQzhmTblEzpR70V0wbV7g76FwWBmVAJqQWKwF65KGtU4llfQcS1VUOdvqmA1jtR1PkSg7jF5zdyewsxy9dvqQ3x0pKQa1lDReEg2vTUEhvQlsruQ2t7HiRASPaZsraj2msSRzsLRwrjdOew= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780439205; c=relaxed/simple; bh=kvx7ohWUkAQAus2rwaNLkjOFJjKkcGh6ZwBZcSaUuvk=; h=Date:To:From:Subject:Message-Id; b=RhhG+t/Yl5tTXYPQPmNAmvykxWGGEcDPUh/mJ1WyQKS8ULoUXGuyaZdu6NBLpz2k8HFajvqGC+7VhLexpih4zdJLwwXw9V8+FWdj3189tT2hCc5FNnkaTbFx3wn2y8YtSKVNclNB9dxnM7rFUw0JziSTC6P3Tn0G/smjEjSika0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=pWI414w+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="pWI414w+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC0181F00893; Tue, 2 Jun 2026 22:26:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1780439203; bh=e1idb4/IemBMh8NiJdrGfqkIk2Q13x9H3oPSA3UM/dA=; h=Date:To:From:Subject; b=pWI414w++5PM2zdyqSUv0lGHx23vKrx0WyHxt19TeVU9bwhh70ISTfqSrydUwQMhz 1/nbJYulFflO3hiJmT2SW7Q1fD/dGJkOc3rm6w/OAkTR8zv6R5+ZXZAlyHy4CaMZib TQumnRoK6FG9VEgVvuz/dRKLe90PyK5Kexzm9KjA= Date: Tue, 02 Jun 2026 15:26:43 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,ryan.roberts@arm.com,npache@redhat.com,ljs@kernel.org,liam@infradead.org,leitao@debian.org,lance.yang@linux.dev,hughd@google.com,dev.jain@arm.com,david@kernel.org,baolin.wang@linux.alibaba.com,baohua@kernel.org,ran.xiaokai@zte.com.cn,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-shmem-refactor-thpsize_shmem_enabled_store-with-sysfs_match_string.patch removed from -mm tree Message-Id: <20260602222643.BC0181F00893@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: shmem: refactor thpsize_shmem_enabled_store() with sysfs_match_string() has been removed from the -mm tree. Its filename was mm-shmem-refactor-thpsize_shmem_enabled_store-with-sysfs_match_string.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Ran Xiaokai Subject: mm: shmem: refactor thpsize_shmem_enabled_store() with sysfs_match_string() Date: Mon, 25 May 2026 10:26:59 +0000 Patch series "refactors thpsize_shmem_enabled_store() and thpsize_shmem_enabled_show()", v4. This patch (of 2): Inspired by commit 82d9ff648c6c ("mm: huge_memory: refactor anon_enabled_store() with set_anon_enabled_mode()"), refactor thpsize_shmem_enabled_store() using sysfs_match_string(). This eliminates the duplicated spin_lock/unlock(), set/clear_bit(), calls across all branches, reducing code duplication. Behavioral change: Call start_stop_khugepaged() only when the mode actually changes. If unchanged, call set_recommended_min_free_kbytes() to preserve legacy watermark behavior. This avoids unnecessary khugepaged restarts. Tested with selftests ./run_kselftest.sh -t mm:ksft_thp.sh, all test cases passed. Link: https://lore.kernel.org/20260525102700.68707-1-ranxiaokai627@163.com Link: https://lore.kernel.org/20260525102700.68707-2-ranxiaokai627@163.com Signed-off-by: Ran Xiaokai Reviewed-by: Baolin Wang Reviewed-by: Barry Song Tested-by: Baolin Wang Tested-by: Lance Yang Acked-by: David Hildenbrand (arm) Reviewed-by: Lorenzo Stoakes Cc: Breno Leitao Cc: Dev Jain Cc: Hugh Dickins Cc: Liam R. Howlett Cc: Nico Pache Cc: Ran Xiaokai Cc: Ryan Roberts Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/shmem.c | 107 ++++++++++++++++++++++++++++----------------------- 1 file changed, 60 insertions(+), 47 deletions(-) --- a/mm/shmem.c~mm-shmem-refactor-thpsize_shmem_enabled_store-with-sysfs_match_string +++ a/mm/shmem.c @@ -5463,6 +5463,29 @@ static ssize_t shmem_enabled_store(struc struct kobj_attribute shmem_enabled_attr = __ATTR_RW(shmem_enabled); static DEFINE_SPINLOCK(huge_shmem_orders_lock); +enum huge_mode { + HUGE_SHMEM_ENABLED_ALWAYS = 0, + HUGE_SHMEM_ENABLED_INHERIT, + HUGE_SHMEM_ENABLED_WITHIN_SIZE, + HUGE_SHMEM_ENABLED_ADVISE, + HUGE_SHMEM_ENABLED_NEVER, +}; + +static const char * const huge_mode_strings[] = { + [HUGE_SHMEM_ENABLED_ALWAYS] = "always", + [HUGE_SHMEM_ENABLED_INHERIT] = "inherit", + [HUGE_SHMEM_ENABLED_WITHIN_SIZE] = "within_size", + [HUGE_SHMEM_ENABLED_ADVISE] = "advise", + [HUGE_SHMEM_ENABLED_NEVER] = "never", +}; + +static unsigned long * const huge_mode_orders[] = { + [HUGE_SHMEM_ENABLED_ALWAYS] = &huge_shmem_orders_always, + [HUGE_SHMEM_ENABLED_INHERIT] = &huge_shmem_orders_inherit, + [HUGE_SHMEM_ENABLED_WITHIN_SIZE] = &huge_shmem_orders_within_size, + [HUGE_SHMEM_ENABLED_ADVISE] = &huge_shmem_orders_madvise, +}; + static ssize_t thpsize_shmem_enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -5483,63 +5506,53 @@ static ssize_t thpsize_shmem_enabled_sho return sysfs_emit(buf, "%s\n", output); } +static bool set_shmem_enabled_mode(int order, enum huge_mode mode) +{ + bool changed = false; + enum huge_mode idx; + + spin_lock(&huge_shmem_orders_lock); + for (idx = 0; idx < ARRAY_SIZE(huge_mode_orders); idx++) { + if (idx == mode) + changed |= !__test_and_set_bit(order, huge_mode_orders[idx]); + else + changed |= __test_and_clear_bit(order, huge_mode_orders[idx]); + } + spin_unlock(&huge_shmem_orders_lock); + + return changed; +} + static ssize_t thpsize_shmem_enabled_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { int order = to_thpsize(kobj)->order; - ssize_t ret = count; + int mode; - if (sysfs_streq(buf, "always")) { - spin_lock(&huge_shmem_orders_lock); - clear_bit(order, &huge_shmem_orders_inherit); - clear_bit(order, &huge_shmem_orders_madvise); - clear_bit(order, &huge_shmem_orders_within_size); - set_bit(order, &huge_shmem_orders_always); - spin_unlock(&huge_shmem_orders_lock); - } else if (sysfs_streq(buf, "inherit")) { - /* Do not override huge allocation policy with non-PMD sized mTHP */ - if (shmem_huge == SHMEM_HUGE_FORCE && !is_pmd_order(order)) - return -EINVAL; - - spin_lock(&huge_shmem_orders_lock); - clear_bit(order, &huge_shmem_orders_always); - clear_bit(order, &huge_shmem_orders_madvise); - clear_bit(order, &huge_shmem_orders_within_size); - set_bit(order, &huge_shmem_orders_inherit); - spin_unlock(&huge_shmem_orders_lock); - } else if (sysfs_streq(buf, "within_size")) { - spin_lock(&huge_shmem_orders_lock); - clear_bit(order, &huge_shmem_orders_always); - clear_bit(order, &huge_shmem_orders_inherit); - clear_bit(order, &huge_shmem_orders_madvise); - set_bit(order, &huge_shmem_orders_within_size); - spin_unlock(&huge_shmem_orders_lock); - } else if (sysfs_streq(buf, "advise")) { - spin_lock(&huge_shmem_orders_lock); - clear_bit(order, &huge_shmem_orders_always); - clear_bit(order, &huge_shmem_orders_inherit); - clear_bit(order, &huge_shmem_orders_within_size); - set_bit(order, &huge_shmem_orders_madvise); - spin_unlock(&huge_shmem_orders_lock); - } else if (sysfs_streq(buf, "never")) { - spin_lock(&huge_shmem_orders_lock); - clear_bit(order, &huge_shmem_orders_always); - clear_bit(order, &huge_shmem_orders_inherit); - clear_bit(order, &huge_shmem_orders_within_size); - clear_bit(order, &huge_shmem_orders_madvise); - spin_unlock(&huge_shmem_orders_lock); - } else { - ret = -EINVAL; - } + mode = sysfs_match_string(huge_mode_strings, buf); + if (mode < 0) + return mode; + + /* Do not override huge allocation policy with non-PMD sized mTHP */ + if (mode == HUGE_SHMEM_ENABLED_INHERIT && + shmem_huge == SHMEM_HUGE_FORCE && !is_pmd_order(order)) + return -EINVAL; - if (ret > 0) { + if (set_shmem_enabled_mode(order, mode)) { int err = start_stop_khugepaged(); - if (err) - ret = err; + return err; + } else { + /* + * Recalculate watermarks even when the mode hasn't changed + * to preserve the legacy behavior, as this is always called + * inside start_stop_khugepaged(). + */ + set_recommended_min_free_kbytes(); } - return ret; + + return count; } struct kobj_attribute thpsize_shmem_enabled_attr = _ Patches currently in -mm which might be from ran.xiaokai@zte.com.cn are