From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 CF807212542 for ; Wed, 8 Apr 2026 15:47:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775663255; cv=none; b=EeVuFY6H398KheqL+9ygbLRiNMfTIn18eC3dWQR2Me1mAHI9XrVGjHPZZESRJe+96xCC0cV1iD5z4+3pJOyLKcoOLI/Ss6G1o5rrkSF7xyFjrUlAO5LP2CHiceqiOdQNFQyKHSrE6/M9BhGLABSTusqec9bH0xhv2okkS2ux8I0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775663255; c=relaxed/simple; bh=/sCYxACzHeKOBBtKbTf0JYBh6CfVPvs9YQezkVa8oQE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=b71zcMd0/uDLQKJqsH3QExU9ooeIcnancAkFRAVD+5uzi6Rfpr0VlJjK7OTO3UnlAlU4J96EoBO+sXKTGsws1te/d9gcVfgARn0o8P2BbbTB2QJOafCFW6FpTXpihKo/UcqidAl8wfkOO9AWOL13uxV/r4q1t9AoqiYU20AiUEI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=UEQzZNC+; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="UEQzZNC+" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:In-Reply-To:References: Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description; bh=g56auhKAY5j+dvmNG9CeuB28V6/CJ5EqcS41m0jUuFE=; b=UEQzZNC+f7LrCH9J/cy5DtjfSM 8092LqJ1MyKxSiue0T+1tZmMWlQvTOMbzlv8K+x3pPnNYOAlPUmDlFwoHDL1ccPsmyOp2NGrAQUZH u2sGsbmLYxH8ahlhkUeVF207qcX3fWNLbKWKeO0DUbXJhVH54IID0/NIx2CB0XTvJOIbU13CA+0Fx d2u98SjvgckTKKqW151JTDvlZ8R2urpx+DkEzhH77iNfO9rguHMWT1jbrWYf6aaJRlTI3gJro9Ns3 gg8KuwAVWLdcVsvou1Ahm7sRYgeL+iVDeogo/DdArgk8+GGdYpkv8nfG8N7+9tcG6pDkK/fth7gf0 WtxhX12A==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wAV7q-008Wdy-22; Wed, 08 Apr 2026 15:47:30 +0000 From: Breno Leitao Date: Wed, 08 Apr 2026 08:47:00 -0700 Subject: [PATCH v2 1/2] mm: huge_memory: use sysfs_match_string() in defrag_store() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260408-thp_defrag-v2-1-bc544c1bde4e@debian.org> References: <20260408-thp_defrag-v2-0-bc544c1bde4e@debian.org> In-Reply-To: <20260408-thp_defrag-v2-0-bc544c1bde4e@debian.org> To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Breno Leitao , kernel-team@meta.com X-Mailer: b4 0.16-dev-453a6 X-Developer-Signature: v=1; a=openpgp-sha256; l=4937; i=leitao@debian.org; h=from:subject:message-id; bh=/sCYxACzHeKOBBtKbTf0JYBh6CfVPvs9YQezkVa8oQE=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBp1niIWX4L/u4+a9VuF0VbZDMLGe4Jc6QrcS85Z NJRBgw8Y7KJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCadZ4iAAKCRA1o5Of/Hh3 bWyBD/9t7F391FzPemA6wI+p/T1F7yuIR/Frzv64pDqioDHGIAkFzQBcdEMOty8LAlNgOpioAHT AO4kjK+OBn2+jGezyf68sukbQuxCOioVuade3ueVws2wNn5JCz8itLc6p7AIEUaRduPpCLZSWnS dvMIYUqL1sZXUKNOZTckmRuRgMNSa01drx1bV6Xj3zf8l+f63jJnp8GMhLch1jSf1TBzDdLlmPy edbNel9XFzhA7b3fg3iwUtyjI7gOV7FaFdgBGkMTVOH+LTx8oUFVbhGnCEy+LVt9AOs0RjjwHpa Xo72K/0BRWtPeoQVmI69drU2tJOz59U7IPF4xtGFjQKHRL/0va5CZReh2oNA1FfEBwkpO9WDdGc aXcEpnDyF3vxygqx+3LuPtk0VQlc5s4Fas88NFW0Aw3LopG8+kqQVNF1RiCqp/HMwUrUM+OC7+4 4rwfiWrPibc9k4zGF0IcRf5YDgO1BEu+xr5TRCQojStEF5EKmM+ZXTN2x56kI6AP4AjAUsbD1gr kd65zFRDxFkzzTmdTx5TsZ9MLhZQJdIIAw/5oIms2K4nk+gnc952rFyYA2fZmzkqqK4kTTQKs0X sQFmfLwbZ7z+lnRfQWobqP+LbxVOOKJK48lSlThZpP2+5Mb+OZx4V52cZCJFD0o/KxhbuNUhUK5 RRQ5MsGsBkAuE5w== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao Replace the if/else chain of sysfs_streq() calls in defrag_store() with sysfs_match_string() and a defrag_mode_strings[] table. Introduce enum defrag_mode and defrag_flags[] array mapping each mode to its corresponding transparent_hugepage_flag. The store function now loops over defrag_flags[], setting the bit for the selected mode and clearing the others. When mode is DEFRAG_NEVER (index 4), no index in the 4-element defrag_flags[] matches, so all flags are cleared. Note that the enum ordering (always, defer, defer+madvise, madvise, never) differs from the original if/else chain order in defrag_store() (always, defer+madvise, defer, madvise, never). This is intentional to match the display order used by defrag_show(). This is a follow-up cleanup to commit 522dfb4ba71f ("mm: huge_memory: refactor anon_enabled_store() with change_anon_orders()") which applied the same sysfs_match_string() pattern to anon_enabled_store(). Acked-by: David Hildenbrand (Arm) Tested-by: Lance Yang Reviewed-by: Lance Yang Reviewed-by: Barry Song Signed-off-by: Breno Leitao --- mm/huge_memory.c | 60 ++++++++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 26 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 970e077019b75..76f2d32428c7f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -429,6 +429,29 @@ ssize_t single_hugepage_flag_store(struct kobject *kobj, return count; } +enum defrag_mode { + DEFRAG_ALWAYS = 0, + DEFRAG_DEFER, + DEFRAG_DEFER_MADVISE, + DEFRAG_MADVISE, + DEFRAG_NEVER, +}; + +static const char * const defrag_mode_strings[] = { + [DEFRAG_ALWAYS] = "always", + [DEFRAG_DEFER] = "defer", + [DEFRAG_DEFER_MADVISE] = "defer+madvise", + [DEFRAG_MADVISE] = "madvise", + [DEFRAG_NEVER] = "never", +}; + +static const enum transparent_hugepage_flag defrag_flags[] = { + [DEFRAG_ALWAYS] = TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, + [DEFRAG_DEFER] = TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, + [DEFRAG_DEFER_MADVISE] = TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, + [DEFRAG_MADVISE] = TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, +}; + static ssize_t defrag_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -456,34 +479,19 @@ static ssize_t defrag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { - if (sysfs_streq(buf, "always")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "defer+madvise")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "defer")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "madvise")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "never")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - } else + int mode, m; + + mode = sysfs_match_string(defrag_mode_strings, buf); + if (mode < 0) return -EINVAL; + for (m = 0; m < ARRAY_SIZE(defrag_flags); m++) { + if (m == mode) + set_bit(defrag_flags[m], &transparent_hugepage_flags); + else + clear_bit(defrag_flags[m], &transparent_hugepage_flags); + } + return count; } static struct kobj_attribute defrag_attr = __ATTR_RW(defrag); -- 2.52.0