From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: "chenliang (T)" <chenliang88@huawei.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] ????: [PATCH v2 06/43] Return path: socket_writev_buffer:?Block even on non-blocking fd's
Date: Tue, 12 Aug 2014 10:36:32 +0100 [thread overview]
Message-ID: <20140812093632.GD2384@work-vm> (raw)
In-Reply-To: <047A6D07C7C75B4D95D277304F90FDF22198BEC4@SZXEML506-MBS.china.huawei.com>
* chenliang (T) (chenliang88@huawei.com) wrote:
>
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The return path uses a non-blocking fd so as not to block waiting for the (possibly broken) destination to finish returning a message, however we still want outbound data to behave in the same way and block.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>
> Hi David
> It is confusing why don't use blocking fd?
I want to make sure that if the destination guest hung during
sending a return path command, that the source wouldn't block
the main thread (in which I'm currently processing the RP commands).
Paolo made a suggestion to move the RP processing to a separate
thread, which would also avoid the problem, and I'll be trying that.
Dave
> Best regards
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2014-08-12 9:42 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-11 14:29 [Qemu-devel] [PATCH v2 00/43] Postcopy implementation Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 01/43] qemu_ram_foreach_block: pass up error value, and down the ramblock name Dr. David Alan Gilbert (git)
2014-08-11 18:29 ` Eric Blake
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 02/43] improve DPRINTF macros, add to savevm Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 03/43] Add qemu_get_counted_string to read a string prefixed by a count byte Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 04/43] Create MigrationIncomingState Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 05/43] Return path: Open a return path on QEMUFile for sockets Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 06/43] Return path: socket_writev_buffer: Block even on non-blocking fd's Dr. David Alan Gilbert (git)
2014-08-12 2:13 ` [Qemu-devel] 答复: " chenliang (T)
2014-08-12 9:36 ` Dr. David Alan Gilbert [this message]
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 07/43] Migration commands Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 08/43] Return path: Control commands Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 09/43] Return path: Send responses from destination to source Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 10/43] Return path: Source handling of return path Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 11/43] qemu_loadvm errors and debug Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 12/43] ram_debug_dump_bitmap: Dump a migration bitmap as text Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 13/43] Rework loadvm path for subloops Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 14/43] Add migration-capability boolean for postcopy-ram Dr. David Alan Gilbert (git)
2014-08-11 16:47 ` Eric Blake
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 15/43] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 16/43] QEMU_VM_CMD_PACKAGED: Send a packaged chunk of migration stream Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 17/43] migrate_init: Call from savevm Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 18/43] Allow savevm handlers to state whether they could go into postcopy Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 19/43] postcopy: OS support test Dr. David Alan Gilbert (git)
2014-08-12 5:32 ` zhanghailiang
2014-08-12 8:18 ` Dr. David Alan Gilbert
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 20/43] migrate_start_postcopy: Command to trigger transition to postcopy Dr. David Alan Gilbert (git)
2014-08-11 17:01 ` Eric Blake
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 21/43] MIG_STATE_POSTCOPY_ACTIVE: Add new migration state Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 22/43] qemu_savevm_state_complete: Postcopy changes Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 23/43] Postcopy: Maintain sentmap during postcopy pre phase Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 24/43] Postcopy page-map-incoming (PMI) structure Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 25/43] postcopy: Add incoming_init/cleanup functions Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 26/43] postcopy: Incoming initialisation Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 27/43] postcopy: ram_enable_notify to switch on userfault Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 28/43] Postcopy: postcopy_start Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 29/43] Postcopy: Rework migration thread for postcopy mode Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 30/43] mig fd_connect: open return path Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 31/43] Postcopy: Create a fault handler thread before marking the ram as userfault Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 32/43] Page request: Add MIG_RPCOMM_REQPAGES reverse command Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 33/43] Page request: Process incoming page request Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 34/43] Page request: Consume pages off the post-copy queue Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 35/43] Add assertion to check migration_dirty_pages Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 36/43] postcopy_ram.c: place_page and helpers Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 37/43] Postcopy: Use helpers to map pages during migration Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 38/43] qemu_ram_block_from_host Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 39/43] Postcopy; Handle userfault requests Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 40/43] Start up a postcopy/listener thread ready for incoming page data Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 41/43] postcopy: Wire up loadvm_postcopy_ram_handle_{run, end} commands Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 42/43] End of migration for postcopy Dr. David Alan Gilbert (git)
2014-08-11 14:29 ` [Qemu-devel] [PATCH v2 43/43] Start documenting how postcopy works Dr. David Alan Gilbert (git)
2014-08-11 17:19 ` Eric Blake
2014-08-11 17:58 ` Dr. David Alan Gilbert
2014-08-12 1:50 ` [Qemu-devel] [PATCH v2 00/43] Postcopy implementation zhanghailiang
2014-08-12 9:19 ` Dr. David Alan Gilbert
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