Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751681AbbLUDVi (ORCPT ); Sun, 20 Dec 2015 22:21:38 -0500 Received: from mail-ig0-f178.google.com ([209.85.213.178]:35227 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145AbbLUDVg (ORCPT ); Sun, 20 Dec 2015 22:21:36 -0500 MIME-Version: 1.0 In-Reply-To: <20151221023237.GB20661@kmo-pixel> References: <20aa515947cdc15799f520f904ad99a2@lycos.com> <20151221023237.GB20661@kmo-pixel> Date: Mon, 21 Dec 2015 11:21:35 +0800 Message-ID: Subject: Re: IO errors after "block: remove bio_get_nr_vecs()" From: Ming Lei To: Kent Overstreet Cc: "Artem S. Tashkinov" , Linus Torvalds , Christoph Hellwig , Ming Lin , Jens Axboe , "Artem S. Tashkinov" , Steven Whitehouse , Tejun Heo , IDE-ML , Linux Kernel Mailing List , "Martin K. Petersen" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1503 Lines: 43 On Mon, Dec 21, 2015 at 10:25 AM, Artem S. Tashkinov wrote: > # cat > /sys/block/sda/queue/{max_hw_sectors_kb,max_sectors_kb,max_segments,max_segment_size} > 32767 > 32767 > 168 > 65536 Looks it is fine, then maybe it is related with BIOVEC_PHYS_MERGEABLE(), BIOVEC_SEG_BOUNDARY() or sort of thing, because dma_addr_t and phys_addr_t turn to 64-bit with PAE, but 'unsigned long' and 'void *' is still 32bit. It was confirmed that there isn't the issue if PAE is disabled. Dumping both sata/ahci hw sg table and bio's bvec might be helpful. On Mon, Dec 21, 2015 at 10:32 AM, Kent Overstreet wrote: > > oy vey. WTF's been happening in blk-merge.c? > > Theyy're not the same bug. The bug in your thread was introduced by Jens in > 5014c311ba "block: fix bogus compiler warnings in blk-merge.c", where he screwed > up the bvprv handling - but that patch comes after the patch Artem bisected to. > > blk_bio_segment_split() looks correct in b54ffb73ca. Yes, that is why reverting 578270bfb(block: fix segment split) can make the issue disappear, because 5014c311ba "block: fix bogus compiler warnings in blk-merge.c" basically disables sg-merge and prevents the issue from being triggered. Thanks, Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/