Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751663Ab1BITDD (ORCPT ); Wed, 9 Feb 2011 14:03:03 -0500 Received: from daytona.panasas.com ([67.152.220.89]:29527 "EHLO daytona.panasas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751235Ab1BITDA (ORCPT ); Wed, 9 Feb 2011 14:03:00 -0500 Message-ID: <4D52E4E1.7070705@panasas.com> Date: Wed, 09 Feb 2011 21:02:57 +0200 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.15) Gecko/20101027 Fedora/3.0.10-1.fc12 Thunderbird/3.0.10 MIME-Version: 1.0 To: Dan Williams , linux-kernel , linux-fsdevel , NeilBrown , uml-devel Subject: Regression with calibrate_xor_blocks, probably UML related Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 09 Feb 2011 19:02:59.0196 (UTC) FILETIME=[F7B3DBC0:01CBC88B] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4979 Lines: 117 I have a new module that uses the async_tx.h lib. On an exact same module code based on 3.6.37 I see the: xor: measuring software checksum speed 8regs : 11312.000 MB/sec 8regs_prefetch: 9792.800 MB/sec 32regs : 11220.400 MB/sec 32regs_prefetch: 9750.800 MB/sec xor: using function: 8regs (11312.000 MB/sec) And all is well. But on code based on 2.6.38-rc4 I get hard stuck right after: xor: measuring software checksum speed the UML is completely frozen. When I kill the uml from the host I can sometimes get this trace. 750c7498: [<6005f936>] bad_page+0xd8/0xf3 750c74c8: [<60060c93>] get_page_from_freelist+0x333/0x47b 750c7508: [<60131243>] put_dec+0x20/0x3c 750c75a0: [<6001a0ac>] change_pre_exec+0x0/0x24 750c75b8: [<60060ef1>] __alloc_pages_nodemask+0x116/0x65b 750c7668: [<60132e25>] sprintf+0xa1/0xa3 750c76a0: [<6001a0ac>] change_pre_exec+0x0/0x24 750c76b8: [<60061446>] __get_free_pages+0x10/0x43 750c76c8: [<60012875>] alloc_stack+0x1b/0x1d 750c76d8: [<6001fe27>] run_helper+0x26/0x1b5 750c76e8: [<60021553>] set_signals+0x1c/0x2e 750c7708: [<6007efac>] __kmalloc+0x9e/0xc4 750c7748: [<6001a544>] change+0x124/0x189 750c77e8: [<601b77db>] _raw_spin_unlock+0x9/0xb 750c7818: [<6001a5a9>] close_addr+0x0/0x1c 750c7828: [<6001a5c3>] close_addr+0x1a/0x1c 750c7838: [<6001926a>] iter_addresses+0x5f/0x76 750c7858: [<6007e8e8>] kfree+0x92/0x9b 750c7898: [<60022d01>] tuntap_close+0x24/0x38 750c78b8: [<600194e4>] close_devices+0x4a/0x7f 750c78d8: [<600121bf>] do_uml_exitcalls+0x12/0x23 750c78f8: [<60012cd2>] uml_cleanup+0x1a/0x87 750c7928: [<6002039b>] last_ditch_exit+0x9/0x16 750c79e8: [<78817031>] xor_8regs_2+0x31/0x58 [xor] 750c7a18: [<7881b000>] calibrate_xor_blocks+0x0/0xdf [xor] 750c7aa8: [<601b77ce>] _raw_spin_unlock_irqrestore+0x18/0x1c 750c7ac8: [<60029d8d>] try_to_wake_up+0x86/0x98 750c7d78: [<601b548d>] printk+0xa0/0xa3 750c7e08: [<78817633>] do_xor_speed+0x54/0xaf [xor] 750c7e20: [<7881b000>] calibrate_xor_blocks+0x0/0xdf [xor] 750c7e58: [<7881b057>] calibrate_xor_blocks+0x57/0xdf [xor] 750c7e68: [<7881b000>] calibrate_xor_blocks+0x0/0xdf [xor] 750c7e78: [<6001105a>] do_one_initcall+0x76/0x121 750c7eb8: [<600563fd>] sys_init_module+0x78/0x1a6 750c7ee8: [<60014d60>] handle_syscall+0x58/0x70 750c7f08: [<60024163>] userspace+0x2dd/0x38a 750c7fc8: [<600126af>] fork_handler+0x62/0x69 (gdb) list *(xor_8regs_2+0x31) 0x55 is in xor_8regs_2 (/usr0/export/dev/bharrosh/git/pub/scsi-misc/include/asm-generic/xor.h:29). 24 p1[0] ^= p2[0]; 25 p1[1] ^= p2[1]; 26 p1[2] ^= p2[2]; 27 p1[3] ^= p2[3]; 28 p1[4] ^= p2[4]; 29 p1[5] ^= p2[5]; 30 p1[6] ^= p2[6]; 31 p1[7] ^= p2[7]; 32 p1 += 8; 33 p2 += 8; (gdb) list *(calibrate_xor_blocks+0x0) 0xd52 is in calibrate_xor_blocks (/usr0/export/dev/bharrosh/git/pub/scsi-misc/crypto/xor.c:101). 96 speed / 1000, speed % 1000); 97 } 98 99 static int __init 100 calibrate_xor_blocks(void) 101 { 102 void *b1, *b2; 103 struct xor_block_template *f, *fastest; 104 105 /* (gdb) list *(do_xor_speed+0x54) 0x657 is in do_xor_speed (/usr0/export/dev/bharrosh/git/pub/scsi-misc/crypto/xor.c:84). 79 now = jiffies; 80 count = 0; 81 while (jiffies == now) { 82 mb(); /* prevent loop optimzation */ 83 tmpl->do_2(BENCH_SIZE, b1, b2); 84 mb(); 85 count++; 86 mb(); 87 } 88 if (count > max) (gdb) list *(calibrate_xor_blocks+0x57) 0xda9 is in calibrate_xor_blocks (/usr0/export/dev/bharrosh/git/pub/scsi-misc/crypto/xor.c:137). 132 "checksumming function: %s\n", 133 fastest->name); 134 xor_speed(fastest); 135 } else { 136 printk(KERN_INFO "xor: measuring software checksum speed\n"); 137 XOR_TRY_TEMPLATES; 138 fastest = template_list; 139 for (f = fastest; f; f = f->next) 140 if (f->speed > fastest->speed) 141 fastest = f; (gdb) q So it looks like the code in UML links the include/asm-generic/xor.h and that it gets stuck. Any thing changed in this area in last merge window? Before I start the very difficult bisect? Thanks for any tips Boaz -- 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/