| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20121116151840.GE22320@phenom.dumpdata.com> Date: Fri, 16 Nov 2012 10:18:40 -0500 From: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com> To: Annie Li <annie.li@...cle.com> Cc: xen-devel@...ts.xensource.com, netdev@...r.kernel.org, Ian.Campbell@...rix.com Subject: Re: [PATCH 0/4] Implement persistent grant in xen-netfront/netback On Thu, Nov 15, 2012 at 03:03:07PM +0800, Annie Li wrote: > This patch implements persistent grants for xen-netfront/netback. This > mechanism maintains page pools in netback/netfront, these page pools is used to > save grant pages which are mapped. This way improve performance which is wasted > when doing grant operations. > > Current netback/netfront does map/unmap grant operations frequently when > transmitting/receiving packets, and grant operations costs much cpu clock. In > this patch, netfront/netback maps grant pages when needed and then saves them > into a page pool for future use. All these pages will be unmapped when > removing/releasing the net device. > > In netfront, two pools are maintained for transmitting and receiving packets. > When new grant pages are needed, the driver gets grant pages from this pool > first. If no free grant page exists, it allocates new page, maps it and then > saves it into the pool. The pool size for transmit/receive is exactly tx/rx > ring size. The driver uses memcpy(not grantcopy) to copy data grant pages. > Here, memcpy is copying the whole page size data. I tried to copy len size data > from offset, but network does not seem work well. I am trying to find the root > cause now. > > In netback, it also maintains two page pools for tx/rx. When netback gets a > request, it does a search first to find out whether the grant reference of > this request is already mapped into its page pool. If the grant ref is mapped, > the address of this mapped page is gotten and memcpy is used to copy data > between grant pages. However, if the grant ref is not mapped, a new page is > allocated, mapped with this grant ref, and then saved into page pool for > future use. Similarly, memcpy replaces grant copy to copy data between grant > pages. In this implementation, two arrays(gnttab_tx_vif,gnttab_rx_vif) are > used to save vif pointer for every request because current netback is not > per-vif based. This would be changed after implementing 1:1 model in netback. > > This patch supports both persistent-grant and non persistent grant. A new > xenstore key "feature-persistent-grants" is used to represent this feature. > > This patch is based on linux3.4-rc3. I hit netperf/netserver failure on > linux latest version v3.7-rc1, v3.7-rc2 and v3.7-rc4. Not sure whether this > netperf/netserver failure connects compound page commit in v3.7-rc1, but I did > hit BUG_ON with debug patch from thread > http://lists.xen.org/archives/html/xen-devel/2012-10/msg00893.html FYI, I get this: 477.814511] BUG: sleeping function called from invalid context at /home/konrad/ssd/linux/mm/page_alloc.c:2487 [ 477.815281] in_atomic(): 1, irqs_disabled(): 1, pid: 3017, name: netperf [ 477.815281] Pid: 3017, comm: netperf Not tainted 3.5.0upstream-00004-g69047bb #1 [ 477.815281] Call Trace: [ 477.815281] [<ffffffff810b990a>] __might_sleep+0xda/0x100 [ 477.815281] [<ffffffff81142e93>] __alloc_pages_nodemask+0x223/0x920 [ 477.815281] [<ffffffff81158439>] ? zone_statistics+0x99/0xc0 [ 477.815281] [<ffffffff81076e79>] ? default_spin_lock_flags+0x9/0x10 [ 477.815281] [<ffffffff81615e3a>] ? _raw_spin_lock_irqsave+0x3a/0x50 [ 477.815281] [<ffffffff81076e79>] ? default_spin_lock_flags+0x9/0x10 [ 477.815281] [<ffffffff81098977>] ? lock_timer_base+0x37/0x70 [ 477.815281] [<ffffffff8109a03d>] ? mod_timer_pending+0x11d/0x230 [ 477.815281] [<ffffffff81616144>] ? _raw_spin_unlock_bh+0x24/0x30 [ 477.815281] [<ffffffff8117e7e1>] alloc_pages_current+0xb1/0x110 [ 477.815281] [<ffffffffa0034238>] xennet_alloc_tx_ref+0x78/0x1c0 [xen_netfront] [ 477.815281] [<ffffffffa00344eb>] xennet_start_xmit+0x16b/0x9f0 [xen_netfront] [ 477.815281] [<ffffffff814c69eb>] dev_hard_start_xmit+0x2fb/0x6f0 [ 477.815281] [<ffffffff814e4566>] sch_direct_xmit+0x116/0x1e0 [ 477.815281] [<ffffffff814c6f6a>] dev_queue_xmit+0x18a/0x6b0 [ 477.815281] [<ffffffff8151264e>] ip_finish_output+0x18e/0x300 [ 477.815281] [<ffffffff81512821>] ip_output+0x61/0xa0 [ 477.815281] [<ffffffff81511b82>] ? __ip_local_out+0xa2/0xb0 [ 477.815281] [<ffffffff81511bb4>] ip_local_out+0x24/0x30 [ 477.815281] [<ffffffff81511ffe>] ip_queue_xmit+0x15e/0x410 [ 477.815281] [<ffffffff81528354>] tcp_transmit_skb+0x424/0x8f0 [ 477.815281] [<ffffffff8152a8c2>] tcp_write_xmit+0x1f2/0x9c0 [ 477.815281] [<ffffffff81182194>] ? ksize+0x14/0x70 [ 477.815281] [<ffffffff8152b711>] __tcp_push_pending_frames+0x21/0x90 [ 477.815281] [<ffffffff8151db23>] tcp_sendmsg+0x983/0xcd0 [ 477.815281] [<ffffffff81540daf>] inet_sendmsg+0x7f/0xd0 [ 477.815281] [<ffffffff81290dde>] ? selinux_socket_sendmsg+0x1e/0x20 [ 477.815281] [<ffffffff814aed13>] sock_sendmsg+0xf3/0x120 [ 477.815281] [<ffffffff81076f48>] ? pvclock_clocksource_read+0x58/0xd0 [ 477.815281] [<ffffffff812de7c0>] ? timerqueue_add+0x60/0xb0 [ 477.815281] [<ffffffff810b0b85>] ? enqueue_hrtimer+0x25/0xb0 [ 477.815281] [<ffffffff814af4d4>] sys_sendto+0x104/0x140 [ 477.815281] [<ffffffff81041279>] ? xen_clocksource_read+0x39/0x50 [ 477.815281] [<ffffffff81041419>] ? xen_clocksource_get_cycles+0x9/0x10 [ 477.815281] [<ffffffff810d3242>] ? getnstimeofday+0x52/0xe0 [ 477.815281] [<ffffffff8161dfb9>] system_call_fastpath+0x16/0x1b > > > Annie Li (4): > xen/netback: implements persistent grant with one page pool. > xen/netback: Split one page pool into two(tx/rx) page pool. > Xen/netfront: Implement persistent grant in netfront. > fix code indent issue in xen-netfront. > > drivers/net/xen-netback/common.h | 24 ++- > drivers/net/xen-netback/interface.c | 26 +++ > drivers/net/xen-netback/netback.c | 215 ++++++++++++++++++-- > drivers/net/xen-netback/xenbus.c | 14 ++- > drivers/net/xen-netfront.c | 378 +++++++++++++++++++++++++++++------ > 5 files changed, 570 insertions(+), 87 deletions(-) > > -- > 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists