From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932308AbbA2BqY (ORCPT ); Wed, 28 Jan 2015 20:46:24 -0500 Received: from userp1050.oracle.com ([156.151.31.82]:44679 "EHLO userp1050.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755449AbbA2BqT (ORCPT ); Wed, 28 Jan 2015 20:46:19 -0500 X-Greylist: delayed 2111 seconds by postgrey-1.27 at vger.kernel.org; Wed, 28 Jan 2015 20:46:19 EST From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: iamjoonsoo.kim@lge.com, m.szyprowski@samsung.com, akpm@linux-foundation.org, lauraa@codeaurora.org, Sasha Levin Subject: [PATCH v4 3/3] mm: cma: release trigger Date: Wed, 28 Jan 2015 14:10:11 -0500 Message-Id: <1422472211-32387-4-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1422472211-32387-1-git-send-email-sasha.levin@oracle.com> References: <1422472211-32387-1-git-send-email-sasha.levin@oracle.com> X-Source-IP: acsinet21.oracle.com [141.146.126.237] X-Source-IP: userp1040.oracle.com [156.151.31.81] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/mm/cma_debug.c b/mm/cma_debug.c index 5bd6863..c29f029 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -39,6 +39,59 @@ 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 { + 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 +138,9 @@ 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