From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id 66C026B0044 for ; Wed, 25 Apr 2012 21:50:53 -0400 (EDT) Message-ID: <4F98AA1D.1040009@kernel.org> Date: Thu, 26 Apr 2012 10:51:25 +0900 From: Minchan Kim MIME-Version: 1.0 Subject: Re: [PATCH 4/6] zsmalloc: add/fix function comment References: <1335334994-22138-1-git-send-email-minchan@kernel.org> <1335334994-22138-5-git-send-email-minchan@kernel.org> <4F97FBB1.1090001@vflare.org> In-Reply-To: <4F97FBB1.1090001@vflare.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Nitin Gupta Cc: Greg Kroah-Hartman , Seth Jennings , Dan Magenheimer , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On 04/25/2012 10:27 PM, Nitin Gupta wrote: > On 04/25/2012 02:23 AM, Minchan Kim wrote: > >> Add/fix the comment. >> >> Signed-off-by: Minchan Kim >> --- >> drivers/staging/zsmalloc/zsmalloc-main.c | 15 +++++++++++---- >> 1 file changed, 11 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c >> index 0fe4cbb..b7d31cc 100644 >> --- a/drivers/staging/zsmalloc/zsmalloc-main.c >> +++ b/drivers/staging/zsmalloc/zsmalloc-main.c >> @@ -565,12 +565,9 @@ EXPORT_SYMBOL_GPL(zs_destroy_pool); >> * zs_malloc - Allocate block of given size from pool. >> * @pool: pool to allocate from >> * @size: size of block to allocate >> - * @page: page no. that holds the object >> - * @offset: location of object within page >> * >> * On success, identifies block allocated >> - * and 0 is returned. On failure, is set to >> - * 0 and -ENOMEM is returned. >> + * and is returned. On failure, NULL is returned. >> * > > > The returned value indeed encodes values as a 'void *' > but this should not be part of the function documentation since its an > internal detail. So, its probably better to say: > > On success, handle to the allocated object is returned; NULL otherwise. Fair enough. > > On a side note, we should also 'typedef void * zs_handle' to avoid any > confusion. Without this, users may just treat zs_malloc return value as > a pointer and try to deference it. Yes. We should do it. I will make it as another patch in next spin. > >> * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. >> */ >> @@ -666,6 +663,16 @@ void zs_free(struct zs_pool *pool, void *obj) >> } >> EXPORT_SYMBOL_GPL(zs_free); >> >> +/** >> + * zs_map_object - get address of allocated object from handle. >> + * @pool: object allocated pool > > > should be: @pool: pool from which the object was allocated > >> + * @handle: handle returned from zs_malloc >> + * > >> + * Before using object allocated from zs_malloc, object >> + * should be mapped to page table by this function. >> + * After using object, call zs_unmap_object to unmap page >> + * table. >> + */ > > > We are not really unmapping any page tables, so could be written as: > > Before using an object allocated from zs_malloc, it must be mapped using > this function. When done with the object, it must be unmapped using > zs_unmap_object > > > Sorry for nitpicking. Never nitpicking. Confusing documentation makes people very hang so documentation is very important. Nitin, Thanks! > > Thanks, > Nitin > > -- > 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/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: email@kvack.org > -- Kind regards, Minchan Kim -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org