From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753810AbbK0C3y (ORCPT ); Thu, 26 Nov 2015 21:29:54 -0500 Received: from mail-pa0-f53.google.com ([209.85.220.53]:35255 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753692AbbK0C3x (ORCPT ); Thu, 26 Nov 2015 21:29:53 -0500 Date: Fri, 27 Nov 2015 11:30:53 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Andrew Morton , Kyeongdon Kim , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: Re: [PATCH v2 3/3] zram: pass gfp from zcomp frontend to backend Message-ID: <20151127023053.GC4220@swordfish> References: <1448430673-10766-3-git-send-email-minchan@kernel.org> <20151127020510.GA4220@swordfish> <20151127021945.GB4220@swordfish> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151127021945.GB4220@swordfish> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (11/27/15 11:19), Sergey Senozhatsky wrote: [..] > > > +static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp, gfp_t flags) > > > { > > > + zstrm = zcomp_strm_alloc(comp, GFP_NOIO|__GFP_NORETRY| > > > + __GFP_NOWARN|__GFP_NOMEMALLOC); > > > > > > and it seems that after 3/3 (v2) we also lost GFP_ZERO for private > > allocation. kzalloc->kmalloc, and no explicit __GFP_ZERO for __vmalloc(). > > > > well, we probably don't really need __GFP_ZERO for ->private, but > let's address it in a separate patch, not as an undocumented change. hm... something like this perhaps. I don't think there any security issues with removing __GFP_ZERO, we have 'garbage' in ->private anyway. zram/zcomp: do not zero out zcomp private pages Do not __GFP_ZERO allocated zcomp ->private pages. We keep allocated streams around and use them for read/write requests, so we supply a zeroed out ->private to compression algorithm as a scratch buffer only once -- the first time we use that stream. For the rest of IO requests served by this stream ->private usually contains some temporarily data from the previous requests. --- diff --git a/drivers/block/zram/zcomp_lz4.c b/drivers/block/zram/zcomp_lz4.c index dc2338d..0110086 100644 --- a/drivers/block/zram/zcomp_lz4.c +++ b/drivers/block/zram/zcomp_lz4.c @@ -19,10 +19,10 @@ static void *zcomp_lz4_create(gfp_t flags) { void *ret; - ret = kzalloc(LZ4_MEM_COMPRESS, flags); + ret = kmalloc(LZ4_MEM_COMPRESS, flags); if (!ret) ret = __vmalloc(LZ4_MEM_COMPRESS, - flags | __GFP_ZERO | __GFP_HIGHMEM, + flags | __GFP_HIGHMEM, PAGE_KERNEL); return ret; } diff --git a/drivers/block/zram/zcomp_lzo.c b/drivers/block/zram/zcomp_lzo.c index 0ab6fce..ed7a1f0 100644 --- a/drivers/block/zram/zcomp_lzo.c +++ b/drivers/block/zram/zcomp_lzo.c @@ -19,10 +19,10 @@ static void *lzo_create(gfp_t flags) { void *ret; - ret = kzalloc(LZO1X_MEM_COMPRESS, flags); + ret = kmalloc(LZO1X_MEM_COMPRESS, flags); if (!ret) ret = __vmalloc(LZO1X_MEM_COMPRESS, - flags | __GFP_ZERO | __GFP_HIGHMEM, + flags | __GFP_HIGHMEM, PAGE_KERNEL); return ret; }