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 49D196453 for ; Tue, 22 Mar 2022 21:46:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B859C340EE; Tue, 22 Mar 2022 21:46:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985575; bh=RZk32U2wkpIOQUJvahJ71fz2IWCApZYl7wNieg6vRYk=; h=Date:To:From:In-Reply-To:Subject:From; b=NoVE+Vijy36uDUoTptgMWu633gboe8ANZ77+QSIL93sbpeSoW6AFsnHkDJpxcc6wj qutkvzmUc/DrNA7oTuMTQ2LIvfY/ES0g8sP/dpov9jXpIpIFZdtSnzckKWNMVoBRf+ hunfFRtRniKuk/SDxiyhJsMXrxPZSNaMuXAGvLcs= Date: Tue, 22 Mar 2022 14:46:14 -0700 To: sourabhjain@linux.ibm.com,osalvador@suse.de,mpe@ellerman.id.au,mike.kravetz@oracle.com,mahesh@linux.ibm.com,david@redhat.com,hbathini@linux.ibm.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 152/227] mm/cma: provide option to opt out from exposing pages on activation failure Message-Id: <20220322214615.0B859C340EE@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Hari Bathini Subject: mm/cma: provide option to opt out from exposing pages on activation failure Patch series "powerpc/fadump: handle CMA activation failure appropriately", v3. Commit 072355c1cf2d ("mm/cma: expose all pages to the buddy if activation of an area fails") started exposing all pages to buddy allocator on CMA activation failure. But there can be CMA users that want to handle the reserved memory differently on CMA allocation failure. Provide an option to opt out from exposing pages to buddy for such cases. Link: https://lkml.kernel.org/r/20220117075246.36072-1-hbathini@linux.ibm.com Link: https://lkml.kernel.org/r/20220117075246.36072-2-hbathini@linux.ibm.com Signed-off-by: Hari Bathini Reviewed-by: David Hildenbrand Cc: Oscar Salvador Cc: Mike Kravetz Cc: Mahesh Salgaonkar Cc: Sourabh Jain Cc: Michael Ellerman Signed-off-by: Andrew Morton --- include/linux/cma.h | 2 ++ mm/cma.c | 11 +++++++++-- mm/cma.h | 1 + 3 files changed, 12 insertions(+), 2 deletions(-) --- a/include/linux/cma.h~mm-cma-provide-option-to-opt-out-from-exposing-pages-on-activation-failure +++ a/include/linux/cma.h @@ -58,4 +58,6 @@ extern bool cma_pages_valid(struct cma * extern bool cma_release(struct cma *cma, const struct page *pages, unsigned long count); extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data); + +extern void cma_reserve_pages_on_error(struct cma *cma); #endif --- a/mm/cma.c~mm-cma-provide-option-to-opt-out-from-exposing-pages-on-activation-failure +++ a/mm/cma.c @@ -131,8 +131,10 @@ not_in_zone: bitmap_free(cma->bitmap); out_error: /* Expose all pages to the buddy, they are useless for CMA. */ - for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++) - free_reserved_page(pfn_to_page(pfn)); + if (!cma->reserve_pages_on_error) { + for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++) + free_reserved_page(pfn_to_page(pfn)); + } totalcma_pages -= cma->count; cma->count = 0; pr_err("CMA area %s could not be activated\n", cma->name); @@ -150,6 +152,11 @@ static int __init cma_init_reserved_area } core_initcall(cma_init_reserved_areas); +void __init cma_reserve_pages_on_error(struct cma *cma) +{ + cma->reserve_pages_on_error = true; +} + /** * cma_init_reserved_mem() - create custom contiguous area from reserved memory * @base: Base address of the reserved area --- a/mm/cma.h~mm-cma-provide-option-to-opt-out-from-exposing-pages-on-activation-failure +++ a/mm/cma.h @@ -30,6 +30,7 @@ struct cma { /* kobject requires dynamic object */ struct cma_kobject *cma_kobj; #endif + bool reserve_pages_on_error; }; extern struct cma cma_areas[MAX_CMA_AREAS]; _