From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 823DCC83F12 for ; Mon, 28 Aug 2023 08:52:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E5018E0010; Mon, 28 Aug 2023 04:52:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 894AE8E000E; Mon, 28 Aug 2023 04:52:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 75C6F8E0010; Mon, 28 Aug 2023 04:52:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 63FB68E000E for ; Mon, 28 Aug 2023 04:52:24 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 3370EC0342 for ; Mon, 28 Aug 2023 08:52:24 +0000 (UTC) X-FDA: 81172897008.24.9B3882F Received: from out-242.mta0.migadu.com (out-242.mta0.migadu.com [91.218.175.242]) by imf27.hostedemail.com (Postfix) with ESMTP id 515EF4001C for ; Mon, 28 Aug 2023 08:52:21 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=o3l1IVK7; spf=pass (imf27.hostedemail.com: domain of muchun.song@linux.dev designates 91.218.175.242 as permitted sender) smtp.mailfrom=muchun.song@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693212741; a=rsa-sha256; cv=none; b=scFw+FakomwT1UPBgP9RmBrUPG9IE2kX86AzenGWNNXwXDX+JS6BQYApK4wMJOhRHqxx/n /tfq3L04ZW/0RAT2t7Clb8d6jzqLTQzjN9b++HzcgTOcuYTSAJ46vyMKUnwyK3gU9m0mKz 7COZ3d4U4ghLayVz6d5czAcJ64calSE= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=o3l1IVK7; spf=pass (imf27.hostedemail.com: domain of muchun.song@linux.dev designates 91.218.175.242 as permitted sender) smtp.mailfrom=muchun.song@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693212741; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=HEJsS6jb2rjW3BlTwJdUWZlMga7O4tMNsD6ueh6tNuo=; b=fELxNcSU35NiY7XKDMnxEyBc/5i+jFe8M4KOBcNbZr6xf0HoIFEWKQlD2LptGKnUU9VtmI 7GQEI9aQzCToQR7qIxnyvCASb7SeVGhYGNNupM8z7OH6ooGB9WiEnQ9C6BVUB8UI6Lcjf9 h9hitrslKbgYsFbQ2AveycFRze4p2Xg= Message-ID: <2be1ab83-f047-245f-68ad-62c4478914a5@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1693212739; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HEJsS6jb2rjW3BlTwJdUWZlMga7O4tMNsD6ueh6tNuo=; b=o3l1IVK7r0+Z4CQcoBcbchRU5K6PCrcAkToafNCBk26Klx80OUlGIoybH+neXCeigVeDQ6 esOYi1Os6Q/MdJgN51tIUDj7sgIedjc0kfYu4Fu3E96cHSbCNx27fmLWYOBzXeywvDvJvq STtbusveaKpFLJgPkSukqCG/0I48vz0= Date: Mon, 28 Aug 2023 16:52:10 +0800 MIME-Version: 1.0 Subject: Re: [v3 3/4] memblock: introduce MEMBLOCK_RSRV_NOINIT_VMEMMAP flag To: Mike Rapoport , Usama Arif Cc: linux-mm@kvack.org, mike.kravetz@oracle.com, linux-kernel@vger.kernel.org, songmuchun@bytedance.com, fam.zheng@bytedance.com, liangma@liangbit.com, punit.agrawal@bytedance.com References: <20230825111836.1715308-1-usama.arif@bytedance.com> <20230825111836.1715308-4-usama.arif@bytedance.com> <20230828074729.GC3223@kernel.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: <20230828074729.GC3223@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 515EF4001C X-Stat-Signature: wkezj9tgzk3ng6gqhu511jts5rmq98rf X-Rspam-User: X-HE-Tag: 1693212741-71798 X-HE-Meta: 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 xxBE5cnz s2ZSj6q0x+XQBtAQKL5dy7RRjLWcIdzDbxcpCcDaPf9NBLFWIHmI6kj/pFLAMBMCxmgys4lMaN4GlJf5U9U3RFq0Zyk0TDgjyFHzuL/RM9Ak1Lte3pOyxtgChq1neqHBAVyWKE3idwEjNSeIsh148orlGGX5T7YSVrYzGfWnkmEZXntqGc8TtqdQSyoiEViu/eBpc X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2023/8/28 15:47, Mike Rapoport wrote: > On Fri, Aug 25, 2023 at 12:18:35PM +0100, Usama Arif wrote: >> For reserved memory regions marked with this flag, >> reserve_bootmem_region is not called during memmap_init_reserved_pages. >> This can be used to avoid struct page initialization for >> regions which won't need them, for e.g. hugepages with >> HVO enabled. >> >> Signed-off-by: Usama Arif >> --- >> include/linux/memblock.h | 10 ++++++++++ >> mm/memblock.c | 32 +++++++++++++++++++++++++++----- >> 2 files changed, 37 insertions(+), 5 deletions(-) >> >> diff --git a/include/linux/memblock.h b/include/linux/memblock.h >> index f71ff9f0ec81..6d681d053880 100644 >> --- a/include/linux/memblock.h >> +++ b/include/linux/memblock.h >> @@ -40,6 +40,8 @@ extern unsigned long long max_possible_pfn; >> * via a driver, and never indicated in the firmware-provided memory map as >> * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the >> * kernel resource tree. >> + * @MEMBLOCK_RSRV_NOINIT_VMEMMAP: memory region for which struct pages are >> + * not initialized (only for reserved regions). >> */ >> enum memblock_flags { >> MEMBLOCK_NONE = 0x0, /* No special request */ >> @@ -47,6 +49,8 @@ enum memblock_flags { >> MEMBLOCK_MIRROR = 0x2, /* mirrored region */ >> MEMBLOCK_NOMAP = 0x4, /* don't add to kernel direct mapping */ >> MEMBLOCK_DRIVER_MANAGED = 0x8, /* always detected via a driver */ >> + /* don't initialize struct pages associated with this reserver memory block */ >> + MEMBLOCK_RSRV_NOINIT_VMEMMAP = 0x10, > The flag means that struct page shouldn't be initialized, it may be used > not only by vmemmap optimizations. > Please drop _VMEMMAP. The area at where the struct pages located is vmemmap, I think the "vmemap" suffix does not mean that it is for "vmemmap optimization", it could specify the target which will not be initialized. For me, MEMBLOCK_RSRV_NOINIT does not tell me what should not be initialized, memblock itself or its struct page (aka vmemmap pages)? So maybe the suffix is better to keep? > > And I agree with Muchun's remarks about the comments. > > > >> }; >> >> /** >> @@ -125,6 +129,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); >> int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); >> int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); >> int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); >> +int memblock_reserved_mark_noinit_vmemmap(phys_addr_t base, phys_addr_t size); > memblock does not care about vmemmap, please drop _vmemmap here and below as well. > >> void memblock_free_all(void); >> void memblock_free(void *ptr, size_t size); >> @@ -259,6 +264,11 @@ static inline bool memblock_is_nomap(struct memblock_region *m) >> return m->flags & MEMBLOCK_NOMAP; >> } >> >> +static inline bool memblock_is_noinit_vmemmap(struct memblock_region *m) > memblock_is_reserved_noinit please. > >> +{ >> + return m->flags & MEMBLOCK_RSRV_NOINIT_VMEMMAP; >> +} >> + >> static inline bool memblock_is_driver_managed(struct memblock_region *m) >> { >> return m->flags & MEMBLOCK_DRIVER_MANAGED; >> diff --git a/mm/memblock.c b/mm/memblock.c >> index 43cb4404d94c..a9782228c840 100644 >> --- a/mm/memblock.c >> +++ b/mm/memblock.c >> @@ -991,6 +991,23 @@ int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size) >> return memblock_setclr_flag(&memblock.memory, base, size, 0, MEMBLOCK_NOMAP); >> } >> >> +/** >> + * memblock_reserved_mark_noinit_vmemmap - Mark a reserved memory region with flag >> + * MEMBLOCK_RSRV_NOINIT_VMEMMAP. > this should be about what marking RSRV_NOINIT does, not what flag it uses > >> + * @base: the base phys addr of the region >> + * @size: the size of the region >> + * >> + * struct pages will not be initialized for reserved memory regions marked with >> + * %MEMBLOCK_RSRV_NOINIT_VMEMMAP. >> + * >> + * Return: 0 on success, -errno on failure. >> + */ >> +int __init_memblock memblock_reserved_mark_noinit_vmemmap(phys_addr_t base, phys_addr_t size) >> +{ >> + return memblock_setclr_flag(&memblock.reserved, base, size, 1, >> + MEMBLOCK_RSRV_NOINIT_VMEMMAP); >> +} >> + >> static bool should_skip_region(struct memblock_type *type, >> struct memblock_region *m, >> int nid, int flags) >> @@ -2107,13 +2124,18 @@ static void __init memmap_init_reserved_pages(void) >> memblock_set_node(start, end, &memblock.reserved, nid); >> } >> >> - /* initialize struct pages for the reserved regions */ >> + /* >> + * initialize struct pages for reserved regions that don't have >> + * the MEMBLOCK_RSRV_NOINIT_VMEMMAP flag set >> + */ >> for_each_reserved_mem_region(region) { >> - nid = memblock_get_region_node(region); >> - start = region->base; >> - end = start + region->size; >> + if (!memblock_is_noinit_vmemmap(region)) { >> + nid = memblock_get_region_node(region); >> + start = region->base; >> + end = start + region->size; >> >> - reserve_bootmem_region(start, end, nid); >> + reserve_bootmem_region(start, end, nid); >> + } >> } >> } >> >> -- >> 2.25.1 >>