From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754883AbbATRjj (ORCPT ); Tue, 20 Jan 2015 12:39:39 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:26152 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754562AbbATRjA (ORCPT ); Tue, 20 Jan 2015 12:39:00 -0500 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 3/3] mm: cma: release trigger Date: Tue, 20 Jan 2015 12:38:33 -0500 Message-Id: <1421775513-4460-4-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1421775513-4460-1-git-send-email-sasha.levin@oracle.com> References: <1421775513-4460-1-git-send-email-sasha.levin@oracle.com> X-Source-IP: ucsinet21.oracle.com [156.151.31.93] 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 eda0a41..7bb1da1 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "cma.h" @@ -64,6 +65,59 @@ static void cma_add_to_cma_mem_list(struct cma_mem *mem) spin_unlock(&cma_mem_head_lock); } +static struct cma_mem *cma_get_entry_from_list(void) +{ + 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(int count) +{ + struct cma_mem *mem = NULL; + + while (count) { + mem = cma_get_entry_from_list(); + if (mem == NULL) + return 0; + + if (mem->n <= count) { + cma_release(dma_contiguous_default_area, mem->p, mem->n); + pr_info("CMA: Freeing %lu pages from %p.\n", + mem->n, mem->p); + count -= mem->n; + kfree(mem); + } else { + cma_release(dma_contiguous_default_area, mem->p, count); + pr_info("CMA: Freeing %d pages from %p.\n", + count, mem->p); + mem->p += count; + mem->n -= count; + count = 0; + cma_add_to_cma_mem_list(mem); + } + } + + return 0; + +} + +static int cma_free_write(void *data, u64 val) +{ + int pages = val; + + return cma_free_mem(pages); +} + +DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n"); + static int cma_alloc_mem(int count) { struct cma_mem *mem; @@ -109,6 +163,8 @@ static int __init cma_debugfs_init(void) debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, NULL, &cma_alloc_fops); + debugfs_create_file("free", S_IWUSR, cma_debugfs_root, NULL, + &cma_free_fops); for (i = 0; i < cma_area_count; i++) cma_debugfs_add_one(&cma_areas[i], i); -- 1.7.10.4