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 884D01CEAC2 for ; Fri, 18 Jul 2025 03:21:51 +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=1752808911; cv=none; b=CUaKVEucMA26CdlYGlEPBv4wmiO0vOYq/rwySkwiQPXul+8sEbORcHQGcWq5+DO7RBLF/nOvtnGdVdh1FmzFZx1QHGWV821kqK64ofeFx+UBqBiCOpXn9H61PhpM9x+EtAE4/I3FjNdXRhd0fkuUHty5UTj0rG8+F0pAy86W7Fk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752808911; c=relaxed/simple; bh=Nbdl65Tk9hUb+2+hPsjkSf/NdIff7lVjRoAqlheIt7s=; h=Date:To:From:Subject:Message-Id; b=p7BvzLsDmfenlh95TDDBiuegsPck3fMe8bnYpA1s5upbpK/vNKCJ1s6KOSsnkMgBxuhAibaFe0MjfWFDyVqeNx3Uui0WAMllD+TfqSrSlGjpGjxKIGgK3F8s2NQQRZN9vjWbk693KdmGLPk+SlGgeY2e3OIPmrQDJqh9rRb/pn0= 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=E7JjYx55; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="E7JjYx55" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F093DC4CEE3; Fri, 18 Jul 2025 03:21:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1752808911; bh=Nbdl65Tk9hUb+2+hPsjkSf/NdIff7lVjRoAqlheIt7s=; h=Date:To:From:Subject:From; b=E7JjYx556CxZbhHVt9jIk+41EOfrhfP0LigCMp/x0lvPuIbVo7IzcLFkOrboi64or JdbVusECZ5FJQlfsphbNy8Qkw++F/UyWJ0K6hiTbrmsUcC2Kw+toQYPCd5GyDAyp7d SDICHio2jmq3FTTLg06hhC9gy/fpoYHHcCYCetjw= Date: Thu, 17 Jul 2025 20:21:50 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,vschneid@redhat.com,vincent.guittot@linaro.org,vbabka@suse.cz,urezki@gmail.com,surenb@google.com,shikemeng@huaweicloud.com,ryan.roberts@arm.com,rppt@kernel.org,rostedt@goodmis.org,peterz@infradead.org,paulmck@kernel.org,nphamcs@gmail.com,npache@redhat.com,neeraj.upadhyay@kernel.org,mingo@redhat.com,mhocko@suse.com,mgorman@suse.de,mathieu.desnoyers@efficios.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,kasong@tencent.com,juri.lelli@redhat.com,josh@joshtriplett.org,jiangshanlai@gmail.com,frederic@kernel.org,dietmar.eggemann@arm.com,dev.jain@arm.com,david@redhat.com,dave@stgolabs.net,chrisl@kernel.org,bsegall@google.com,boqun.feng@gmail.com,bhe@redhat.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,liuye@kylinos.cn,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion.patch added to mm-new branch Message-Id: <20250718032150.F093DC4CEE3@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: replace (20 - PAGE_SHIFT) with common macros for pages<->MB conversion has been added to the -mm mm-new branch. Its filename is mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion.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. 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 the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ye Liu Subject: mm: replace (20 - PAGE_SHIFT) with common macros for pages<->MB conversion Date: Fri, 18 Jul 2025 10:41:32 +0800 Replace repeated (20 - PAGE_SHIFT) calculations with standard macros: - MB_TO_PAGES(mb) converts MB to page count - PAGES_TO_MB(pages) converts pages to MB No functional change. Link: https://lkml.kernel.org/r/20250718024134.1304745-1-ye.liu@linux.dev Signed-off-by: Ye Liu Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Ben Segall Cc: Boqun Feng Cc: Chris Li Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: Dev Jain Cc: Dietmar Eggemann Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Josh Triplett Cc: Juri Lelli Cc: Kairui Song Cc: Kemeng Shi Cc: Lai jiangshan Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mariano Pache Cc: Mathieu Desnoyers Cc: Mel Gorman Cc: Michal Hocko Cc: Mike Rapoport Cc: Neeraj Upadhyay Cc: Nhat Pham Cc: "Paul E . McKenney" Cc: Peter Zijlstra Cc: Ryan Roberts Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: "Uladzislau Rezki (Sony)" Cc: Valentin Schneider Cc: Vincent Guittot Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton --- include/linux/mm.h | 9 +++++++++ kernel/rcu/rcuscale.c | 2 +- kernel/sched/fair.c | 5 ++--- mm/backing-dev.c | 2 +- mm/huge_memory.c | 2 +- mm/swap.c | 2 +- 6 files changed, 15 insertions(+), 7 deletions(-) --- a/include/linux/mm.h~mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion +++ a/include/linux/mm.h @@ -69,6 +69,15 @@ static inline void totalram_pages_add(lo extern void * high_memory; +/* + * Convert between pages and MB + * 20 is the shift for 1MB (2^20 = 1MB) + * PAGE_SHIFT is the shift for page size (e.g., 12 for 4KB pages) + * So (20 - PAGE_SHIFT) converts between pages and MB + */ +#define PAGES_TO_MB(pages) ((pages) >> (20 - PAGE_SHIFT)) +#define MB_TO_PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) + #ifdef CONFIG_SYSCTL extern int sysctl_legacy_va_layout; #else --- a/kernel/rcu/rcuscale.c~mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion +++ a/kernel/rcu/rcuscale.c @@ -796,7 +796,7 @@ kfree_scale_thread(void *arg) pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n", (unsigned long long)(end_time - start_time), kfree_loops, rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started), - (mem_begin - mem_during) >> (20 - PAGE_SHIFT)); + PAGES_TO_MB(mem_begin - mem_during)); if (shutdown) { smp_mb(); /* Assign before wake. */ --- a/kernel/sched/fair.c~mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion +++ a/kernel/sched/fair.c @@ -1512,7 +1512,7 @@ static unsigned int task_nr_scan_windows * by the PTE scanner and NUMA hinting faults should be trapped based * on resident pages */ - nr_scan_pages = sysctl_numa_balancing_scan_size << (20 - PAGE_SHIFT); + nr_scan_pages = MB_TO_PAGES(sysctl_numa_balancing_scan_size); rss = get_mm_rss(p->mm); if (!rss) rss = nr_scan_pages; @@ -1949,8 +1949,7 @@ bool should_numa_migrate_memory(struct t } def_th = sysctl_numa_balancing_hot_threshold; - rate_limit = sysctl_numa_balancing_promote_rate_limit << \ - (20 - PAGE_SHIFT); + rate_limit = MB_TO_PAGES(sysctl_numa_balancing_promote_rate_limit); numa_promotion_adjust_threshold(pgdat, rate_limit, def_th); th = pgdat->nbp_threshold ? : def_th; --- a/mm/backing-dev.c~mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion +++ a/mm/backing-dev.c @@ -510,7 +510,7 @@ static void wb_update_bandwidth_workfn(s /* * Initial write bandwidth: 100 MB/s */ -#define INIT_BW (100 << (20 - PAGE_SHIFT)) +#define INIT_BW MB_TO_PAGES(100) static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, gfp_t gfp) --- a/mm/huge_memory.c~mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion +++ a/mm/huge_memory.c @@ -911,7 +911,7 @@ static int __init hugepage_init(void) * where the extra memory used could hurt more than TLB overhead * is likely to save. The admin can still enable it through /sys. */ - if (totalram_pages() < (512 << (20 - PAGE_SHIFT))) { + if (totalram_pages() < MB_TO_PAGES(512)) { transparent_hugepage_flags = 0; return 0; } --- a/mm/swap.c~mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion +++ a/mm/swap.c @@ -1096,7 +1096,7 @@ static const struct ctl_table swap_sysct */ void __init swap_setup(void) { - unsigned long megs = totalram_pages() >> (20 - PAGE_SHIFT); + unsigned long megs = PAGES_TO_MB(totalram_pages()); /* Use a smaller cluster for small-memory machines */ if (megs < 16) _ Patches currently in -mm which might be from liuye@kylinos.cn are mm-replace-20-page_shift-with-common-macros-for-pages-mb-conversion.patch