From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 5AAFC6B0033 for ; Wed, 18 Jan 2017 21:59:51 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id f144so41460646pfa.3 for ; Wed, 18 Jan 2017 18:59:51 -0800 (PST) Received: from mail-pg0-x244.google.com (mail-pg0-x244.google.com. [2607:f8b0:400e:c05::244]) by mx.google.com with ESMTPS id a5si2091739pgg.89.2017.01.18.18.59.50 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Jan 2017 18:59:50 -0800 (PST) Received: by mail-pg0-x244.google.com with SMTP id 75so2856861pgf.3 for ; Wed, 18 Jan 2017 18:59:50 -0800 (PST) Date: Thu, 19 Jan 2017 12:00:04 +0900 From: Sergey Senozhatsky Subject: Re: [Bug 192571] zswap + zram enabled BUG Message-ID: <20170119030004.GA2046@jagdpanzerIV.localdomain> References: <20170117122249.815342d95117c3f444acc952@linux-foundation.org> <20170118013948.GA580@jagdpanzerIV.localdomain> <20170118131711.GA7021@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Dan Streetman Cc: Michal Hocko , Sergey Senozhatsky , sss123next@list.ru, Seth Jennings , Minchan Kim , bugzilla-daemon@bugzilla.kernel.org, Linux-MM , Andrew Morton On (01/18/17 20:36), Dan Streetman wrote: > On Wed, Jan 18, 2017 at 8:17 AM, Michal Hocko wrote: > > On Wed 18-01-17 10:39:48, Sergey Senozhatsky wrote: > >> Cc Dan > >> > >> On (01/17/17 12:22), Andrew Morton wrote: > >> > > https://bugzilla.kernel.org/show_bug.cgi?id=192571 > >> > > > >> > > --- Comment #1 from Gluzskiy Alexandr --- > >> > > [199961.576604] ------------[ cut here ]------------ > >> > > [199961.577830] kernel BUG at mm/zswap.c:1108! > >> > >> zswap didn't manage to decompress the page: > >> > >> static int zswap_frontswap_load(unsigned type, pgoff_t offset, > >> struct page *page) > >> { > >> ... > >> dst = kmap_atomic(page); > >> tfm = *get_cpu_ptr(entry->pool->tfm); > >> ret = crypto_comp_decompress(tfm, src, entry->length, dst, &dlen); > >> put_cpu_ptr(entry->pool->tfm); > >> kunmap_atomic(dst); > >> zpool_unmap_handle(entry->pool->zpool, entry->handle); > >> BUG_ON(ret); > >> ^^^^^^^^^^^ > > > > Ugh, why do we even do that? This is not the way how to handle error > > situations. AFAIU propagating the error out wouldn't be a big deal > > because we would just fallback to regular swap, right? > > yeah this function definitely should never bug; it's just a callback > from the zpool to try to write a page back to the swapcache so the > zpool can free a page. It's definitely ok for it to return an error. > good. Dan, Seth, care to send the patch? and one more thing... can you take a look at [1]? [1] https://marc.info/?l=linux-mm&m=147031191906154&w=4 -ss -- 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/ . Don't email: email@kvack.org