From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 67036900086 for ; Thu, 14 Apr 2011 13:27:12 -0400 (EDT) Message-ID: <4DA72E1C.7090900@fiec.espol.edu.ec> Date: Thu, 14 Apr 2011 12:25:48 -0500 From: =?ISO-8859-1?Q?Alex_Villac=ED=ADs_Lasso?= MIME-Version: 1.0 Subject: Re: [Bugme-new] [Bug 31142] New: Large write to USB stick freezes unrelated tasks for a long time References: <20110321163742.GA24244@csn.ul.ie> <4D878564.6080608@fiec.espol.edu.ec> <20110321201641.GA5698@random.random> <20110322112032.GD24244@csn.ul.ie> <20110322150314.GC5698@random.random> <4D8907C2.7010304@fiec.espol.edu.ec> <20110322214020.GD5698@random.random> <20110323003718.GH5698@random.random> <4D8A2517.3090403@fiec.espol.edu.ec> <4D99E5C8.7090505@fiec.espol.edu.ec> <20110408190912.GI29444@random.random> <4D9F6AB6.6000809@fiec.espol.edu.ec> <4DA47D83.30707@fiec.espol.edu.ec> In-Reply-To: <4DA47D83.30707@fiec.espol.edu.ec> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Mel Gorman , Andrew Morton , avillaci@ceibo.fiec.espol.edu.ec, bugzilla-daemon@bugzilla.kernel.org, bugme-daemon@bugzilla.kernel.org, linux-mm@kvack.org El 12/04/11 11:27, Alex Villaci-s Lasso escribio: >>> === >>> Subject: compaction: reverse the change that forbid sync migraton with __GFP_NO_KSWAPD >>> >>> From: Andrea Arcangeli >>> >>> It's uncertain this has been beneficial, so it's safer to undo it. All other >>> compaction users would still go in synchronous mode if a first attempt of async >>> compaction failed. Hopefully we don't need to force special behavior for THP >>> (which is the only __GFP_NO_KSWAPD user so far and it's the easier to exercise >>> and to be noticeable). This also make __GFP_NO_KSWAPD return to its original >>> strict semantics specific to bypass kswapd, as THP allocations have khugepaged >>> for the async THP allocations/compactions. >>> >>> Signed-off-by: Andrea Arcangeli >>> --- >>> mm/page_alloc.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> --- a/mm/page_alloc.c >>> +++ b/mm/page_alloc.c >>> @@ -2105,7 +2105,7 @@ rebalance: >>> sync_migration); >>> if (page) >>> goto got_pg; >>> - sync_migration = !(gfp_mask& __GFP_NO_KSWAPD); >>> + sync_migration = true; >>> >>> /* Try direct reclaim and then allocating */ >>> page = __alloc_pages_direct_reclaim(gfp_mask, order, >>> >> The stalls occur even with vfat. I am no longer using udf, since (right now) it is not necessary. I will test this patch now. >> > > From preliminary tests, I feel that the patch actually eliminates the stalls. I have just copied nearly 6 GB of data into my USB stick and noticed no application freezes. > I retract that. I have tested 2.6.39-rc3 after a day of having several heavy applications loaded in memory, and the stalls do get worse when reversing the patch. -- 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