1. 13 6月, 2009 24 次提交
  2. 12 6月, 2009 16 次提交
    • P
      slab: setup cpu caches later on when interrupts are enabled · 8429db5c
      Pekka Enberg 提交于
      Fixes the following boot-time warning:
      
        [    0.000000] ------------[ cut here ]------------
        [    0.000000] WARNING: at kernel/smp.c:369 smp_call_function_many+0x56/0x1bc()
        [    0.000000] Hardware name:
        [    0.000000] Modules linked in:
        [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30 #492
        [    0.000000] Call Trace:
        [    0.000000]  [<ffffffff8149e021>] ? _spin_unlock+0x4f/0x5c
        [    0.000000]  [<ffffffff8108f11b>] ? smp_call_function_many+0x56/0x1bc
        [    0.000000]  [<ffffffff81061764>] warn_slowpath_common+0x7c/0xa9
        [    0.000000]  [<ffffffff810617a5>] warn_slowpath_null+0x14/0x16
        [    0.000000]  [<ffffffff8108f11b>] smp_call_function_many+0x56/0x1bc
        [    0.000000]  [<ffffffff810f3e00>] ? do_ccupdate_local+0x0/0x54
        [    0.000000]  [<ffffffff810f3e00>] ? do_ccupdate_local+0x0/0x54
        [    0.000000]  [<ffffffff8108f2be>] smp_call_function+0x3d/0x68
        [    0.000000]  [<ffffffff810f3e00>] ? do_ccupdate_local+0x0/0x54
        [    0.000000]  [<ffffffff81066fd8>] on_each_cpu+0x31/0x7c
        [    0.000000]  [<ffffffff810f64f5>] do_tune_cpucache+0x119/0x454
        [    0.000000]  [<ffffffff81087080>] ? lockdep_init_map+0x94/0x10b
        [    0.000000]  [<ffffffff818133b0>] ? kmem_cache_init+0x421/0x593
        [    0.000000]  [<ffffffff810f69cf>] enable_cpucache+0x68/0xad
        [    0.000000]  [<ffffffff818133c3>] kmem_cache_init+0x434/0x593
        [    0.000000]  [<ffffffff8180987c>] ? mem_init+0x156/0x161
        [    0.000000]  [<ffffffff817f8aae>] start_kernel+0x1cc/0x3b9
        [    0.000000]  [<ffffffff817f829a>] x86_64_start_reservations+0xaa/0xae
        [    0.000000]  [<ffffffff817f837f>] x86_64_start_kernel+0xe1/0xe8
        [    0.000000] ---[ end trace 4eaa2a86a8e2da22 ]---
      
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Nick Piggin <npiggin@suse.de>
      Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      8429db5c
    • P
      slab,slub: don't enable interrupts during early boot · 7e85ee0c
      Pekka Enberg 提交于
      As explained by Benjamin Herrenschmidt:
      
        Oh and btw, your patch alone doesn't fix powerpc, because it's missing
        a whole bunch of GFP_KERNEL's in the arch code... You would have to
        grep the entire kernel for things that check slab_is_available() and
        even then you'll be missing some.
      
        For example, slab_is_available() didn't always exist, and so in the
        early days on powerpc, we used a mem_init_done global that is set form
        mem_init() (not perfect but works in practice). And we still have code
        using that to do the test.
      
      Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
      in early boot code to avoid enabling interrupts.
      Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      7e85ee0c
    • P
      slab: fix gfp flag in setup_cpu_cache() · eb91f1d0
      Pekka Enberg 提交于
      Fixes the following warning during bootup when compiling with CONFIG_SLAB:
      
        [    0.000000] ------------[ cut here ]------------
        [    0.000000] WARNING: at kernel/lockdep.c:2282 lockdep_trace_alloc+0x91/0xb9()
        [    0.000000] Hardware name:
        [    0.000000] Modules linked in:
        [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30 #491
        [    0.000000] Call Trace:
        [    0.000000]  [<ffffffff81087d84>] ? lockdep_trace_alloc+0x91/0xb9
        [    0.000000]  [<ffffffff81061764>] warn_slowpath_common+0x7c/0xa9
        [    0.000000]  [<ffffffff810617a5>] warn_slowpath_null+0x14/0x16
        [    0.000000]  [<ffffffff81087d84>] lockdep_trace_alloc+0x91/0xb9
        [    0.000000]  [<ffffffff810f5b03>] kmem_cache_alloc_node_notrace+0x26/0xdf
        [    0.000000]  [<ffffffff81487f4e>] ? setup_cpu_cache+0x7e/0x210
        [    0.000000]  [<ffffffff81487fe3>] setup_cpu_cache+0x113/0x210
        [    0.000000]  [<ffffffff810f73ff>] kmem_cache_create+0x409/0x486
        [    0.000000]  [<ffffffff818131c1>] kmem_cache_init+0x232/0x593
        [    0.000000]  [<ffffffff8180987c>] ? mem_init+0x156/0x161
        [    0.000000]  [<ffffffff817f8aae>] start_kernel+0x1cc/0x3b9
        [    0.000000]  [<ffffffff817f829a>] x86_64_start_reservations+0xaa/0xae
        [    0.000000]  [<ffffffff817f837f>] x86_64_start_kernel+0xe1/0xe8
        [    0.000000] ---[ end trace 4eaa2a86a8e2da22 ]---
      Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      eb91f1d0
    • J
      [SCSI] Merge branch 'linus' · 82681a31
      James Bottomley 提交于
      Conflicts:
      	drivers/message/fusion/mptsas.c
      
      fixed up conflict between req->data_len accessors and mptsas driver updates.
      Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      82681a31
    • M
      lguest: add support for indirect ring entries · d1f0132e
      Mark McLoughlin 提交于
      Support the VIRTIO_RING_F_INDIRECT_DESC feature.
      
      This is a simple matter of changing the descriptor walking
      code to operate on a struct vring_desc* and supplying it
      with an indirect table if detected.
      Signed-off-by: NMark McLoughlin <markmc@redhat.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      d1f0132e
    • R
      lguest: suppress notifications in example Launcher · b60da13f
      Rusty Russell 提交于
      The Guest only really needs to tell us about activity when we're going
      to listen to the eventfd: normally, we don't want to know.
      
      So if there are no available buffers, turn on notifications, re-check,
      then wait for the Guest to notify us via the eventfd, then turn
      notifications off again.
      
      There's enough else going on that the differences are in the noise.
      
      Before:				Secs	RxKicks	TxKicks
       1G TCP Guest->Host:		3.94	  4686	  32815
       1M normal pings:		104	142862	1000010
       1M 1k pings (-l 120):		57	142026	1000007
      
      After:
       1G TCP Guest->Host:		3.76	  4691	  32811
       1M normal pings:		111	142859	 997467
       1M 1k pings (-l 120):		55	 19648	 501549
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      b60da13f
    • R
      lguest: try to batch interrupts on network receive · 4a8962e2
      Rusty Russell 提交于
      Rather than triggering an interrupt every time, we only trigger an
      interrupt when there are no more incoming packets (or the recv queue
      is full).
      
      However, the overhead of doing the select to figure this out is
      measurable: 1M pings goes from 98 to 104 seconds, and 1G Guest->Host
      TCP goes from 3.69 to 3.94 seconds.  It's close to the noise though.
      
      I tested various timeouts, including reducing it as the number of
      pending packets increased, timing a 1 gigabyte TCP send from Guest ->
      Host and Host -> Guest (GSO disabled, to increase packet rate).
      
      // time tcpblast -o -s 65536 -c 16k 192.168.2.1:9999 > /dev/null
      
      Timeout		Guest->Host	Pkts/irq	Host->Guest	Pkts/irq
      Before		11.3s		1.0		6.3s		1.0
      0		11.7s		1.0		6.6s		23.5
      1		17.1s		8.8		8.6s		26.0
      1/pending	13.4s		1.9		6.6s		23.8
      2/pending	13.6s		2.8		6.6s		24.1
      5/pending	14.1s		5.0		6.6s		24.4
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      4a8962e2
    • R
      lguest: avoid sending interrupts to Guest when no activity occurs. · 95c517c0
      Rusty Russell 提交于
      If we track how many buffers we've used, we can tell whether we really
      need to interrupt the Guest.  This happens as a side effect of
      spurious notifications.
      
      Spurious notifications happen because it can take a while before the
      Host thread wakes up and sets the VRING_USED_F_NO_NOTIFY flag, and
      meanwhile the Guest can more notifications.
      
      A real fix would be to use wake counts, rather than a suppression
      flag, but the practical difference is generally in the noise: the
      interrupt is usually coalesced into a pending one anyway so we just
      save a system call which isn't clearly measurable.
      
      				Secs	Spurious IRQS
      1G TCP Guest->Host:		3.93	58
      1M normal pings:		100	72
      1M 1k pings (-l 120):		57	492904
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      95c517c0
    • R
      lguest: implement deferred interrupts in example Launcher · 38bc2b8c
      Rusty Russell 提交于
      Rather than sending an interrupt on every buffer, we only send an interrupt
      when we're about to wait for the Guest to send us a new one.  The console
      input and network input still send interrupts manually, but the block device,
      network and console output queues can simply rely on this logic to send
      interrupts to the Guest at the right time.
      
      The patch is cluttered by moving trigger_irq() higher in the code.
      
      In practice, two factors make this optimization less interesting:
      (1) we often only get one input at a time, even for networking,
      (2) triggering an interrupt rapidly tends to get coalesced anyway.
      
      Before:				Secs	RxIRQS	TxIRQs
       1G TCP Guest->Host:		3.72	32784	32771
       1M normal pings:		99	1000004	995541
       100,000 1k pings (-l 120):	5	49510	49058
      
      After:
       1G TCP Guest->Host:		3.69	32809	32769
       1M normal pings:		99	1000004	996196
       100,000 1k pings (-l 120):	5	52435	52361
      
      (Note the interrupt count on 100k pings goes *up*: see next patch).
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      38bc2b8c
    • R
      lguest: remove obsolete LHREQ_BREAK call · 5dac051b
      Rusty Russell 提交于
      We no longer need an efficient mechanism to force the Guest back into
      host userspace, as each device is serviced without bothering the main
      Guest process (aka. the Launcher).
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      5dac051b
    • R
      lguest: have example Launcher service all devices in separate threads · 659a0e66
      Rusty Russell 提交于
      Currently lguest has three threads: the main Launcher thread, a Waker
      thread, and a thread for the block device (because synchronous block
      was simply too painful to bear).
      
      The Waker selects() on all the input file descriptors (eg. stdin, net
      devices, pipe to the block thread) and when one becomes readable it calls
      into the kernel to kick the Launcher thread out into userspace, which
      repeats the poll, services the device(s), and then tells the kernel to
      release the Waker before re-entering the kernel to run the Guest.
      
      Also, to make a slightly-decent network transmit routine, the Launcher
      would suppress further network interrupts while it set a timer: that
      signal handler would write to a pipe, which would rouse the Waker
      which would prod the Launcher out of the kernel to check the network
      device again.
      
      Now we can convert all our virtqueues to separate threads: each one has
      a separate eventfd for when the Guest pokes the device, and can trigger
      interrupts in the Guest directly.
      
      The linecount shows how much this simplifies, but to really bring it
      home, here's an strace analysis of single Guest->Host ping before:
      
      * Guest sends packet, notifies xmit vq, return control to Launcher
      * Launcher clears notification flag on xmit ring
      * Launcher writes packet to TUN device
      	writev(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"\366\r\224`\2058\272m\224vf\274\10\0E\0\0T\0\0@\0@\1\265"..., 98}], 2) = 108
      * Launcher sets up interrupt for Guest (xmit ring is empty)
      	write(10, "\2\0\0\0\3\0\0\0", 8) = 0
      * Launcher sets up timer for interrupt mitigation
      	setitimer(ITIMER_REAL, {it_interval={0, 0}, it_value={0, 505}}, NULL) = 0
      * Launcher re-runs guest
      	pread64(10, 0xbfa5f4d4, 4, 0) ...
      * Waker notices reply packet in tun device (it was in select)
      	select(12, [0 3 4 6 11], NULL, NULL, NULL) = 1 (in [4])
      * Waker kicks Launcher out of guest:
      	pwrite64(10, "\3\0\0\0\1\0\0\0", 8, 0) = 0
      * Launcher returns from running guest:
      	... = -1 EAGAIN (Resource temporarily unavailable)
      * Launcher looks at input fds:
      	select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 1 (in [4], left {0, 0})
      * Launcher reads pong from tun device:
      	readv(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"\272m\224vf\274\366\r\224`\2058\10\0E\0\0T\364\26\0\0@"..., 1518}], 2) = 108
      * Launcher injects guest notification:
      	write(10, "\2\0\0\0\2\0\0\0", 8) = 0
      * Launcher rechecks fds:
      	select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 0 (Timeout)
      * Launcher clears Waker:
      	pwrite64(10, "\3\0\0\0\0\0\0\0", 8, 0) = 0
      * Launcher reruns Guest:
      	pread64(10, 0xbfa5f4d4, 4, 0) = ? ERESTARTSYS (To be restarted)
      * Signal comes in, uses pipe to wake up Launcher:
      	--- SIGALRM (Alarm clock) @ 0 (0) ---
      	write(8, "\0", 1)       = 1
      	sigreturn()             = ? (mask now [])
      * Waker sees write on pipe:
      	select(12, [0 3 4 6 11], NULL, NULL, NULL) = 1 (in [6])
      * Waker kicks Launcher out of Guest:
      	pwrite64(10, "\3\0\0\0\1\0\0\0", 8, 0) = 0
      * Launcher exits from kernel:
      	pread64(10, 0xbfa5f4d4, 4, 0) = -1 EAGAIN (Resource temporarily unavailable)
      * Launcher looks to see what fd woke it:
      	select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 1 (in [6], left {0, 0})
      * Launcher reads timeout fd, sets notification flag on xmit ring
      	read(6, "\0", 32)       = 1
      * Launcher rechecks fds:
      	select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 0 (Timeout)
      * Launcher clears Waker:
      	pwrite64(10, "\3\0\0\0\0\0\0\0", 8, 0) = 0
      * Launcher resumes Guest:
      	pread64(10, "\0p\0\4", 4, 0) ....
      
      strace analysis of single Guest->Host ping after:
      
      * Guest sends packet, notifies xmit vq, creates event on eventfd.
      * Network xmit thread wakes from read on eventfd:
      	read(7, "\1\0\0\0\0\0\0\0", 8)          = 8
      * Network xmit thread writes packet to TUN device
      	writev(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"J\217\232FI\37j\27\375\276\0\304\10\0E\0\0T\0\0@\0@\1\265"..., 98}], 2) = 108
      * Network recv thread wakes up from read on tunfd:
      	readv(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"j\27\375\276\0\304J\217\232FI\37\10\0E\0\0TiO\0\0@\1\214"..., 1518}], 2) = 108
      * Network recv thread sets up interrupt for the Guest
      	write(6, "\2\0\0\0\2\0\0\0", 8) = 0
      * Network recv thread goes back to reading tunfd
      	13:39:42.460285 readv(4,  <unfinished ...>
      * Network xmit thread sets up interrupt for Guest (xmit ring is empty)
      	write(6, "\2\0\0\0\3\0\0\0", 8) = 0
      * Network xmit thread goes back to reading from eventfd
      	read(7, <unfinished ...>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      659a0e66
    • R
      lguest: use eventfds for device notification · df60aeef
      Rusty Russell 提交于
      Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with
      an address: the main Launcher process returns with this address, and figures
      out what device to run.
      
      A far nicer model is to let processes bind an eventfd to an address: if we
      find one, we simply signal the eventfd.
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Cc: Davide Libenzi <davidel@xmailserver.org>
      df60aeef
    • R
      eventfd: export eventfd_signal and eventfd_fget for lguest · 5718607b
      Rusty Russell 提交于
      lguest wants to attach eventfds to guest notifications, and lguest is
      usually a module.
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      To: Davide Libenzi <davidel@xmailserver.org>
      5718607b
    • R
      lguest: allow any process to send interrupts · 9f155a9b
      Rusty Russell 提交于
      We currently only allow the Launcher process to send interrupts, but it
      as we already send interrupts from the hrtimer, it's a simple matter of
      extracting that code into a common set_interrupt routine.
      
      As we switch to a thread per virtqueue, this avoids a bottleneck through the
      main Launcher process.
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      9f155a9b
    • R
      lguest: PAE fixes · 92b4d8df
      Rusty Russell 提交于
      1) j wasn't initialized in setup_pagetables, so they weren't set up for me
         causing immediate guest crashes.
      
      2) gpte_addr should not re-read the pmd from the Guest.  Especially
         not BUG_ON() based on the value.  If we ever supported SMP guests,
         they could trigger that.  And the Launcher could also trigger it
         (tho currently root-only).
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      92b4d8df
    • M
      lguest: PAE support · acdd0b62
      Matias Zabaljauregui 提交于
      This version requires that host and guest have the same PAE status.
      NX cap is not offered to the guest, yet.
      Signed-off-by: NMatias Zabaljauregui <zabaljauregui@gmail.com>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      acdd0b62