From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f169.google.com (mail-ob0-f169.google.com [209.85.214.169]) by kanga.kvack.org (Postfix) with ESMTP id 97E3B6B0081 for ; Thu, 12 Feb 2015 17:27:06 -0500 (EST) Received: by mail-ob0-f169.google.com with SMTP id wp4so13561319obc.0 for ; Thu, 12 Feb 2015 14:27:06 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id v84si189545oig.101.2015.02.12.14.27.05 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 12 Feb 2015 14:27:06 -0800 (PST) From: Sasha Levin Subject: [PATCH v5 3/3] mm: cma: release trigger Date: Thu, 12 Feb 2015 17:26:48 -0500 Message-Id: <1423780008-16727-4-git-send-email-sasha.levin@oracle.com> In-Reply-To: <1423780008-16727-1-git-send-email-sasha.levin@oracle.com> References: <1423780008-16727-1-git-send-email-sasha.levin@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: iamjoonsoo.kim@lge.com, m.szyprowski@samsung.com, akpm@linux-foundation.org, lauraa@codeaurora.org, s.strogin@partner.samsung.com, Sasha Levin Provides a userspace interface to trigger a CMA release. Usage: echo [pages] > free This would provide testing/fuzzing access to the CMA release paths. Signed-off-by: Sasha Levin --- mm/cma_debug.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/mm/cma_debug.c b/mm/cma_debug.c index 5bd6863..6f0b976 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -39,6 +39,60 @@ static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem) spin_unlock(&cma->mem_head_lock); } +static struct cma_mem *cma_get_entry_from_list(struct cma *cma) +{ + struct cma_mem *mem = NULL; + + spin_lock(&cma->mem_head_lock); + if (!hlist_empty(&cma->mem_head)) { + mem = hlist_entry(cma->mem_head.first, struct cma_mem, node); + hlist_del_init(&mem->node); + } + spin_unlock(&cma->mem_head_lock); + + return mem; +} + +static int cma_free_mem(struct cma *cma, int count) +{ + struct cma_mem *mem = NULL; + + while (count) { + mem = cma_get_entry_from_list(cma); + if (mem == NULL) + return 0; + + if (mem->n <= count) { + cma_release(cma, mem->p, mem->n); + count -= mem->n; + kfree(mem); + } else if (cma->order_per_bit == 0) { + cma_release(cma, mem->p, count); + mem->p += count; + mem->n -= count; + count = 0; + cma_add_to_cma_mem_list(cma, mem); + } else { + pr_debug("cma: cannot release partial block when order_per_bit != 0\n"); + cma_add_to_cma_mem_list(cma, mem); + break; + } + } + + return 0; + +} + +static int cma_free_write(void *data, u64 val) +{ + int pages = val; + struct cma *cma = data; + + return cma_free_mem(cma, pages); +} + +DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n"); + static int cma_alloc_mem(struct cma *cma, int count) { struct cma_mem *mem; @@ -85,6 +139,9 @@ static void cma_debugfs_add_one(struct cma *cma, int idx) debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma, &cma_alloc_fops); + debugfs_create_file("free", S_IWUSR, cma_debugfs_root, cma, + &cma_free_fops); + debugfs_create_file("base_pfn", S_IRUGO, tmp, &cma->base_pfn, &cma_debugfs_fops); debugfs_create_file("count", S_IRUGO, tmp, -- 1.7.10.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org