From patchwork Wed Nov 1 22:51:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13443104 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 4B9FD101EF for ; Wed, 1 Nov 2023 22:52:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="k96IOm0g" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698879146; x=1730415146; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=hEIpF+H2iWRMoZGPvwzbL8B1g/l212Q9ts7SomwLAKg=; b=k96IOm0gxpCRgPkpCUU2oQ01qPYQfjw6vAyAs34+kii6Oh2kPqRJJ5/C l6QaDCIJOQdO7Rhysd6h7V0mB+OW5WsmkjVeXDUkEGKH2sOF0RjS1wkPA cbVhqn4zambabNqzpptB4JeA4Q3jpRReBKSIhlYMGhBL6g8sYfX3rbj4D 9q2hN22CP75uM/IgSmXY6wvKeJcddjLJNpxAJUCacvvDt9SX1zZdZlmyy bVF9TRIDho5fkHSoJw6PLNzjy5tJm2v1Zs5TOv45vDGnljA3TX57COcOQ AmQdg7ERUkyvwkumTlOY5/pmeAuB2QBx9OTUz3xioiaDRwXMUp9pHQ6CJ w==; X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="10133610" X-IronPort-AV: E=Sophos;i="6.03,269,1694761200"; d="scan'208";a="10133610" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 15:52:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="796033557" X-IronPort-AV: E=Sophos;i="6.03,269,1694761200"; d="scan'208";a="796033557" Received: from dgopalan-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.98.103]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 15:52:22 -0700 From: Vishal Verma Date: Wed, 01 Nov 2023 16:51:51 -0600 Subject: [PATCH v8 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource() Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231101-vv-kmem_memmap-v8-1-5e4a83331388@intel.com> References: <20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com> In-Reply-To: <20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Michal Hocko , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=1362; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=hEIpF+H2iWRMoZGPvwzbL8B1g/l212Q9ts7SomwLAKg=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlO15aG/1KINNWN2ie9r25S157UB9UxN8TOaWyxuKfd8 6hBxsyuo5SFQYyLQVZMkeXvno+Mx+S25/MEJjjCzGFlAhnCwMUpABNhecXwV47p9dUwJv3W+3aV IXtYrjVW8cQ+C77ucvhiidbLafbvFjEyPJQoOd3km/jN6fxxuX8PJ6VO8QkrNSvJWn/FSjhXzS6 dBQA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF A review of the memmap_on_memory modifications to add_memory_resource() revealed an instance of an open-coded kmemdup(). Replace it with kmemdup(). Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Reported-by: Dan Williams Reviewed-by: David Hildenbrand Signed-off-by: Vishal Verma Reviewed-by: Fan Ni --- mm/memory_hotplug.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index f8d3e7427e32..6be7de9efa55 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1439,11 +1439,11 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { if (mhp_supports_memmap_on_memory(size)) { mhp_altmap.free = memory_block_memmap_on_memory_pages(); - params.altmap = kmalloc(sizeof(struct vmem_altmap), GFP_KERNEL); + params.altmap = kmemdup(&mhp_altmap, + sizeof(struct vmem_altmap), + GFP_KERNEL); if (!params.altmap) goto error; - - memcpy(params.altmap, &mhp_altmap, sizeof(mhp_altmap)); } /* fallback to not using altmap */ } From patchwork Wed Nov 1 22:51:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13443107 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 C203114274 for ; Wed, 1 Nov 2023 22:52:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Tr6Mg9Ce" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698879147; x=1730415147; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=BJVpsauM2TFedbmnVw8A0R+ub3n3nKsAxG13LldkcLQ=; b=Tr6Mg9CelKH7W6nP+ScxbVcWtQM+zH0GAKZ3rlduHUsIRAHjLqRkJe/M 4UzA9yNjUkY8Lb6rIvxeMY5L7rBECFeR4+TQFwFsfd2S+erhX95VvmnOT L5bntQkwR3cZ9sqhGHd8lFYMkh3yNSXZ+QZ+LmPwEWPe5FZ3qEcy8bkPI DB7d/8dB5p5T1srTx++8TRasLdzya0MWQTitBum5rlv2lkVUGr5RbhF9I oC+hT0R7/Ddod0KmA5TjG+aaobT9NNY6V8fU+yD5xaRNY/Ku+jJ3f8oZV oodzH92O9/KwV6XpCKOL5MD0OhbZ2DnaKL9ivrk6M/WapfyS9k6J3PL2+ g==; X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="10133620" X-IronPort-AV: E=Sophos;i="6.03,269,1694761200"; d="scan'208";a="10133620" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 15:52:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="796033560" X-IronPort-AV: E=Sophos;i="6.03,269,1694761200"; d="scan'208";a="796033560" Received: from dgopalan-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.98.103]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 15:52:24 -0700 From: Vishal Verma Date: Wed, 01 Nov 2023 16:51:52 -0600 Subject: [PATCH v8 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231101-vv-kmem_memmap-v8-2-5e4a83331388@intel.com> References: <20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com> In-Reply-To: <20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Michal Hocko , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=9997; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=BJVpsauM2TFedbmnVw8A0R+ub3n3nKsAxG13LldkcLQ=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlO15aW76v3ijU/JueX8Xdj51lPnkr2sOPGN1YzR9o3B HLZ34jrKGVhEONikBVTZPm75yPjMbnt+TyBCY4wc1iZQIYwcHEKwERydjAyHOxeY6nlMmcDX+lX b41bj8ob500vsbYtCf17gfnESV/x84wMu1XSu0oZFYTNZBd+FNl85M20/jc9cV/q9oerm7/8Wt/ EAwA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF The MHP_MEMMAP_ON_MEMORY flag for hotplugged memory is restricted to 'memblock_size' chunks of memory being added. Adding a larger span of memory precludes memmap_on_memory semantics. For users of hotplug such as kmem, large amounts of memory might get added from the CXL subsystem. In some cases, this amount may exceed the available 'main memory' to store the memmap for the memory being added. In this case, it is useful to have a way to place the memmap on the memory being added, even if it means splitting the addition into memblock-sized chunks. Change add_memory_resource() to loop over memblock-sized chunks of memory if caller requested memmap_on_memory, and if other conditions for it are met. Teach try_remove_memory() to also expect that a memory range being removed might have been split up into memblock sized chunks, and to loop through those as needed. This does preclude being able to use PUD mappings in the direct map; a proposal to how this could be optimized in the future is laid out here[1]. [1]: https://lore.kernel.org/linux-mm/b6753402-2de9-25b2-36e9-eacd49752b19@redhat.com/ Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Suggested-by: David Hildenbrand Reviewed-by: Dan Williams Signed-off-by: Vishal Verma Acked-by: David Hildenbrand --- mm/memory_hotplug.c | 213 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 138 insertions(+), 75 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6be7de9efa55..d242e49d7f7b 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1380,6 +1380,84 @@ static bool mhp_supports_memmap_on_memory(unsigned long size) return arch_supports_memmap_on_memory(vmemmap_size); } +static void __ref remove_memory_blocks_and_altmaps(u64 start, u64 size) +{ + unsigned long memblock_size = memory_block_size_bytes(); + u64 cur_start; + + /* + * For memmap_on_memory, the altmaps were added on a per-memblock + * basis; we have to process each individual memory block. + */ + for (cur_start = start; cur_start < start + size; + cur_start += memblock_size) { + struct vmem_altmap *altmap = NULL; + struct memory_block *mem; + + mem = find_memory_block(pfn_to_section_nr(PFN_DOWN(cur_start))); + WARN_ON_ONCE(!mem); + if (!mem) + continue; + + altmap = mem->altmap; + mem->altmap = NULL; + + remove_memory_block_devices(cur_start, memblock_size); + + arch_remove_memory(cur_start, memblock_size, altmap); + + /* Verify that all vmemmap pages have actually been freed. */ + WARN(altmap->alloc, "Altmap not fully unmapped"); + kfree(altmap); + } +} + +static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group, + u64 start, u64 size) +{ + unsigned long memblock_size = memory_block_size_bytes(); + u64 cur_start; + int ret; + + for (cur_start = start; cur_start < start + size; + cur_start += memblock_size) { + struct mhp_params params = { .pgprot = + pgprot_mhp(PAGE_KERNEL) }; + struct vmem_altmap mhp_altmap = { + .base_pfn = PHYS_PFN(cur_start), + .end_pfn = PHYS_PFN(cur_start + memblock_size - 1), + }; + + mhp_altmap.free = memory_block_memmap_on_memory_pages(); + params.altmap = kmemdup(&mhp_altmap, sizeof(struct vmem_altmap), + GFP_KERNEL); + if (!params.altmap) + return -ENOMEM; + + /* call arch's memory hotadd */ + ret = arch_add_memory(nid, cur_start, memblock_size, ¶ms); + if (ret < 0) { + kfree(params.altmap); + goto out; + } + + /* create memory block devices after memory was added */ + ret = create_memory_block_devices(cur_start, memblock_size, + params.altmap, group); + if (ret) { + arch_remove_memory(cur_start, memblock_size, NULL); + kfree(params.altmap); + goto out; + } + } + + return 0; +out: + if (ret && (cur_start != start)) + remove_memory_blocks_and_altmaps(start, cur_start - start); + return ret; +} + /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations (triggered e.g. by sysfs). @@ -1390,10 +1468,6 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) { struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; enum memblock_flags memblock_flags = MEMBLOCK_NONE; - struct vmem_altmap mhp_altmap = { - .base_pfn = PHYS_PFN(res->start), - .end_pfn = PHYS_PFN(res->end), - }; struct memory_group *group = NULL; u64 start, size; bool new_node = false; @@ -1436,28 +1510,22 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) /* * Self hosted memmap array */ - if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { - if (mhp_supports_memmap_on_memory(size)) { - mhp_altmap.free = memory_block_memmap_on_memory_pages(); - params.altmap = kmemdup(&mhp_altmap, - sizeof(struct vmem_altmap), - GFP_KERNEL); - if (!params.altmap) - goto error; + if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) && + mhp_supports_memmap_on_memory(memory_block_size_bytes())) { + ret = create_altmaps_and_memory_blocks(nid, group, start, size); + if (ret) + goto error; + } else { + ret = arch_add_memory(nid, start, size, ¶ms); + if (ret < 0) + goto error; + + /* create memory block devices after memory was added */ + ret = create_memory_block_devices(start, size, NULL, group); + if (ret) { + arch_remove_memory(start, size, NULL); + goto error; } - /* fallback to not using altmap */ - } - - /* call arch's memory hotadd */ - ret = arch_add_memory(nid, start, size, ¶ms); - if (ret < 0) - goto error_free; - - /* create memory block devices after memory was added */ - ret = create_memory_block_devices(start, size, params.altmap, group); - if (ret) { - arch_remove_memory(start, size, NULL); - goto error_free; } if (new_node) { @@ -1494,8 +1562,6 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) walk_memory_blocks(start, size, NULL, online_memory_block); return ret; -error_free: - kfree(params.altmap); error: if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) memblock_remove(start, size); @@ -2062,17 +2128,13 @@ static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) return 0; } -static int test_has_altmap_cb(struct memory_block *mem, void *arg) +static int count_memory_range_altmaps_cb(struct memory_block *mem, void *arg) { - struct memory_block **mem_ptr = (struct memory_block **)arg; - /* - * return the memblock if we have altmap - * and break callback. - */ - if (mem->altmap) { - *mem_ptr = mem; - return 1; - } + u64 *num_altmaps = (u64 *)arg; + + if (mem->altmap) + *num_altmaps += 1; + return 0; } @@ -2146,11 +2208,31 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node); +static int memory_blocks_have_altmaps(u64 start, u64 size) +{ + u64 num_memblocks = size / memory_block_size_bytes(); + u64 num_altmaps = 0; + + if (!mhp_memmap_on_memory()) + return 0; + + walk_memory_blocks(start, size, &num_altmaps, + count_memory_range_altmaps_cb); + + if (num_altmaps == 0) + return 0; + + if (num_memblocks != num_altmaps) { + WARN_ONCE(1, "Not all memblocks in range have altmaps"); + return -EINVAL; + } + + return 1; +} + static int __ref try_remove_memory(u64 start, u64 size) { - struct memory_block *mem; - int rc = 0, nid = NUMA_NO_NODE; - struct vmem_altmap *altmap = NULL; + int rc, nid = NUMA_NO_NODE; BUG_ON(check_hotplug_memory_range(start, size)); @@ -2167,45 +2249,25 @@ static int __ref try_remove_memory(u64 start, u64 size) if (rc) return rc; - /* - * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in - * the same granularity it was added - a single memory block. - */ - if (mhp_memmap_on_memory()) { - rc = walk_memory_blocks(start, size, &mem, test_has_altmap_cb); - if (rc) { - if (size != memory_block_size_bytes()) { - pr_warn("Refuse to remove %#llx - %#llx," - "wrong granularity\n", - start, start + size); - return -EINVAL; - } - altmap = mem->altmap; - /* - * Mark altmap NULL so that we can add a debug - * check on memblock free. - */ - mem->altmap = NULL; - } - } - /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); - /* - * Memory block device removal under the device_hotplug_lock is - * a barrier against racing online attempts. - */ - remove_memory_block_devices(start, size); - mem_hotplug_begin(); - arch_remove_memory(start, size, altmap); - - /* Verify that all vmemmap pages have actually been freed. */ - if (altmap) { - WARN(altmap->alloc, "Altmap not fully unmapped"); - kfree(altmap); + rc = memory_blocks_have_altmaps(start, size); + if (rc < 0) { + goto err; + } else if (rc == 0) { + /* + * Memory block device removal under the device_hotplug_lock is + * a barrier against racing online attempts. + * No altmaps present, do the removal directly + */ + remove_memory_block_devices(start, size); + arch_remove_memory(start, size, NULL); + } else { + /* all memblocks in the range have altmaps */ + remove_memory_blocks_and_altmaps(start, size); } if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { @@ -2218,8 +2280,9 @@ static int __ref try_remove_memory(u64 start, u64 size) if (nid != NUMA_NO_NODE) try_offline_node(nid); +err: mem_hotplug_done(); - return 0; + return (rc < 0 ? rc : 0); } /** From patchwork Wed Nov 1 22:51:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13443106 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 72B5918E38 for ; Wed, 1 Nov 2023 22:52:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JIuo2Gss" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698879150; x=1730415150; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=f/IKjiX0oUHcikJLOo2W8JK83pAYKKgmZaVVmd3uHXA=; b=JIuo2GsslHzlrE3TIhH+NoSfD2GKzWkquFj2IwDPM0FnbQx+IHQ4rykb wvvztYdEClX7tEpXhvVo4wwPXWC2PIw9jlUHkXNjtP4AbV1oq4ivWQA0H zOZn9q4sdvBk7sNidSwilD/uOyFHUJ7l17YVSS79RXVcUcrkNsEQ338ap og8ucE+OtPRFXetXBA450FQJHb41kHBbGfbrKjoSTARr/bf2yt8s2/68n fnmH3+SR464uJpNPOAXu4sBeCRc8Jezha71zR8tQmMsW4adgRQUY6dGkx tkZTr/Z5bCWmhwmJj+mCbOrdX7yJFp6EFB8xhJNeUImrg4PGv3MXqk+24 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="10133632" X-IronPort-AV: E=Sophos;i="6.03,269,1694761200"; d="scan'208";a="10133632" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 15:52:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="796033564" X-IronPort-AV: E=Sophos;i="6.03,269,1694761200"; d="scan'208";a="796033564" Received: from dgopalan-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.98.103]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 15:52:25 -0700 From: Vishal Verma Date: Wed, 01 Nov 2023 16:51:53 -0600 Subject: [PATCH v8 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231101-vv-kmem_memmap-v8-3-5e4a83331388@intel.com> References: <20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com> In-Reply-To: <20231101-vv-kmem_memmap-v8-0-5e4a83331388@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Michal Hocko , Jonathan Cameron , Jeff Moyer , Vishal Verma , Jonathan Cameron X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=5021; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=f/IKjiX0oUHcikJLOo2W8JK83pAYKKgmZaVVmd3uHXA=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlO15YmCtyR/i/bdfNgTbjZxNSCN4xhHx5/i61d42f4d mtvQPnUjlIWBjEuBlkxRZa/ez4yHpPbns8TmOAIM4eVCWQIAxenAEzkyH+GP3wt3llcWzV+HX7w 5D77jTl7UuyUgw3cti8xTuY93ypRx8jw3/3+lb4d9p47+takWa99VNXvxt7QdvVpj5zfn8c7v7X x8wAA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Large amounts of memory managed by the kmem driver may come in via CXL, and it is often desirable to have the memmap for this memory on the new memory itself. Enroll kmem-managed memory for memmap_on_memory semantics if the dax region originates via CXL. For non-CXL dax regions, retain the existing default behavior of hot adding without memmap_on_memory semantics. Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand Reviewed-by: Huang, Ying Signed-off-by: Vishal Verma --- drivers/dax/bus.h | 1 + drivers/dax/dax-private.h | 1 + drivers/dax/bus.c | 3 +++ drivers/dax/cxl.c | 1 + drivers/dax/hmem/hmem.c | 1 + drivers/dax/kmem.c | 8 +++++++- drivers/dax/pmem.c | 1 + 7 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index 1ccd23360124..cbbf64443098 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -23,6 +23,7 @@ struct dev_dax_data { struct dev_pagemap *pgmap; resource_size_t size; int id; + bool memmap_on_memory; }; struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data); diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 27cf2daaaa79..446617b73aea 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -70,6 +70,7 @@ struct dev_dax { struct ida ida; struct device dev; struct dev_pagemap *pgmap; + bool memmap_on_memory; int nr_range; struct dev_dax_range { unsigned long pgoff; diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 0ee96e6fc426..ad9f821b8c78 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -367,6 +367,7 @@ static ssize_t create_store(struct device *dev, struct device_attribute *attr, .dax_region = dax_region, .size = 0, .id = -1, + .memmap_on_memory = false, }; struct dev_dax *dev_dax = devm_create_dev_dax(&data); @@ -1400,6 +1401,8 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) dev_dax->align = dax_region->align; ida_init(&dev_dax->ida); + dev_dax->memmap_on_memory = data->memmap_on_memory; + inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; dev->bus = &dax_bus_type; diff --git a/drivers/dax/cxl.c b/drivers/dax/cxl.c index 8bc9d04034d6..c696837ab23c 100644 --- a/drivers/dax/cxl.c +++ b/drivers/dax/cxl.c @@ -26,6 +26,7 @@ static int cxl_dax_region_probe(struct device *dev) .dax_region = dax_region, .id = -1, .size = range_len(&cxlr_dax->hpa_range), + .memmap_on_memory = true, }; return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index 5d2ddef0f8f5..b9da69f92697 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -36,6 +36,7 @@ static int dax_hmem_probe(struct platform_device *pdev) .dax_region = dax_region, .id = -1, .size = region_idle ? 0 : range_len(&mri->range), + .memmap_on_memory = false, }; return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index c57acb73e3db..0aa6c45a4e5a 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "dax-private.h" #include "bus.h" @@ -56,6 +57,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) unsigned long total_len = 0; struct dax_kmem_data *data; int i, rc, mapped = 0; + mhp_t mhp_flags; int numa_node; /* @@ -136,12 +138,16 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) */ res->flags = IORESOURCE_SYSTEM_RAM; + mhp_flags = MHP_NID_IS_MGID; + if (dev_dax->memmap_on_memory) + mhp_flags |= MHP_MEMMAP_ON_MEMORY; + /* * Ensure that future kexec'd kernels will not treat * this as RAM automatically. */ rc = add_memory_driver_managed(data->mgid, range.start, - range_len(&range), kmem_name, MHP_NID_IS_MGID); + range_len(&range), kmem_name, mhp_flags); if (rc) { dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n", diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index ae0cb113a5d3..f3c6c67b8412 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -63,6 +63,7 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev) .id = id, .pgmap = &pgmap, .size = range_len(&range), + .memmap_on_memory = false, }; return devm_create_dev_dax(&data);