qemu-kvm/SOURCES/kvm-block-coroutine-wrapper-use-qemu_get_current_aio_con.patch

70 lines
2.8 KiB
Diff

From b1a68aebadecd7d339cf5eaffeda15099c998528 Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Tue, 12 Sep 2023 19:10:37 -0400
Subject: [PATCH 095/101] block-coroutine-wrapper: use
qemu_get_current_aio_context()
RH-Author: Kevin Wolf <kwolf@redhat.com>
RH-MergeRequest: 214: Remove AioContext lock
RH-Jira: RHEL-15965
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Commit: [26/26] cde767bcdc626e90721792e3889952057a548ac5 (kmwolf/centos-qemu-kvm)
Use qemu_get_current_aio_context() in mixed wrappers and coroutine
wrappers so that code runs in the caller's AioContext instead of moving
to the BlockDriverState's AioContext. This change is necessary for the
multi-queue block layer where any thread can call into the block layer.
Most wrappers are IO_CODE where it's safe to use the current AioContext
nowadays. BlockDrivers and the core block layer use their own locks and
no longer depend on the AioContext lock for thread-safety.
The bdrv_create() wrapper invokes GLOBAL_STATE code. Using the current
AioContext is safe because this code is only called with the BQL held
from the main loop thread.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230912231037.826804-6-stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
scripts/block-coroutine-wrapper.py | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/scripts/block-coroutine-wrapper.py b/scripts/block-coroutine-wrapper.py
index c9c09fcacd..dbbde99e39 100644
--- a/scripts/block-coroutine-wrapper.py
+++ b/scripts/block-coroutine-wrapper.py
@@ -92,8 +92,6 @@ def __init__(self, wrapper_type: str, return_type: str, name: str,
f"{self.name}")
self.target_name = f'{subsystem}_{subname}'
- self.ctx = self.gen_ctx()
-
self.get_result = 's->ret = '
self.ret = 'return s.ret;'
self.co_ret = 'return '
@@ -167,7 +165,7 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
{func.co_ret}{name}({ func.gen_list('{name}') });
}} else {{
{struct_name} s = {{
- .poll_state.ctx = {func.ctx},
+ .poll_state.ctx = qemu_get_current_aio_context(),
.poll_state.in_progress = true,
{ func.gen_block(' .{name} = {name},') }
@@ -191,7 +189,7 @@ def create_co_wrapper(func: FuncDecl) -> str:
{func.return_type} {func.name}({ func.gen_list('{decl}') })
{{
{struct_name} s = {{
- .poll_state.ctx = {func.ctx},
+ .poll_state.ctx = qemu_get_current_aio_context(),
.poll_state.in_progress = true,
{ func.gen_block(' .{name} = {name},') }
--
2.39.3