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From: Uri Lublin <uril@redhat.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH] migrate.c: migrate_fd_put_buffer: Do not busyloop: stop writing if EWOULDBLOCK
Date: Tue, 19 May 2009 14:08:53 +0300	[thread overview]
Message-ID: <1242731333-1526-1-git-send-email-uril@redhat.com> (raw)

The migration code is non-blocking, designed for live migration.

Practically migrate_fd_put_buffer busy-loops trying to write, as
on many machines EWOULDBLOCK==EAGAIN (look in include/asm-generic/errno.h).

Signed-off-by: Uri Lublin <uril@redhat.com>
---
 migration.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/migration.c b/migration.c
index 859d945..ca397fa 100644
--- a/migration.c
+++ b/migration.c
@@ -176,7 +176,7 @@ ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
 
     do {
         ret = s->write(s, data, size);
-    } while (ret == -1 && ((s->get_error(s)) == EINTR || (s->get_error(s)) == EWOULDBLOCK));
+    } while (ret == -1 && ((s->get_error(s)) == EINTR));
 
     if (ret == -1)
         ret = -(s->get_error(s));
-- 
1.6.0.6

             reply	other threads:[~2009-05-19 11:09 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-19 11:08 Uri Lublin [this message]
2009-05-21  9:32 ` [Qemu-devel] [PATCH] migrate.c: migrate_fd_put_buffer: Do not busyloop: stop writing if EWOULDBLOCK Dor Laor
2009-05-22 13:20   ` Anthony Liguori
2009-05-23 15:55     ` Dor Laor

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