From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: david.edmondson@oracle.com, kwolf@redhat.com, qemu-block@nongnu.org
Subject: [PATCH v5 0/6] coroutine rwlock downgrade fix, minor VDI changes
Date: Wed, 17 Mar 2021 19:00:07 +0100 [thread overview]
Message-ID: <20210317180013.235231-1-pbonzini@redhat.com> (raw)
This is a resubmit of David Edmondson's series at
https://patchew.org/QEMU/20210309144015.557477-1-david.edmondson@oracle.com/.
After closer analysis on IRC, the CoRwlock's attempt to ensure
fairness turned out to be flawed. Therefore, this series
reimplements CoRwlock without using a CoQueue. Tracking whether
each queued coroutine is a reader/writer makes it possible to
never wake a writer when only readers should be allowed and
vice versa.
v2->v3: new CoRwlock implementation
v3->v4: fix upgrade and add a test for that, too
v4->v5: typo
David Edmondson (4):
block/vdi: When writing new bmap entry fails, don't leak the buffer
block/vdi: Don't assume that blocks are larger than VdiHeader
coroutine/mutex: Store the coroutine in the CoWaitRecord only once
test-coroutine: Add rwlock downgrade test
Paolo Bonzini (2):
coroutine-lock: reimplement CoRwlock to fix downgrade bug
test-coroutine: add rwlock upgrade test
block/vdi.c | 11 ++-
include/qemu/coroutine.h | 17 ++--
tests/unit/test-coroutine.c | 161 ++++++++++++++++++++++++++++++++++++
util/qemu-coroutine-lock.c | 149 +++++++++++++++++++++------------
4 files changed, 274 insertions(+), 64 deletions(-)
--
2.29.2
next reply other threads:[~2021-03-17 18:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 18:00 Paolo Bonzini [this message]
2021-03-17 18:00 ` [PATCH 1/6] block/vdi: When writing new bmap entry fails, don't leak the buffer Paolo Bonzini
2021-03-24 14:25 ` Max Reitz
2021-03-17 18:00 ` [PATCH 2/6] block/vdi: Don't assume that blocks are larger than VdiHeader Paolo Bonzini
2021-03-24 14:25 ` Max Reitz
2021-03-17 18:00 ` [PATCH 3/6] coroutine/mutex: Store the coroutine in the CoWaitRecord only once Paolo Bonzini
2021-03-17 18:00 ` [PATCH 4/6] coroutine-lock: reimplement CoRwlock to fix downgrade bug Paolo Bonzini
2021-03-24 16:15 ` Stefan Hajnoczi
2021-03-24 16:40 ` Paolo Bonzini
2021-03-17 18:00 ` [PATCH 5/6] test-coroutine: add rwlock upgrade test Paolo Bonzini
2021-03-17 18:19 ` David Edmondson
2021-03-17 18:00 ` [PATCH 6/6] test-coroutine: Add rwlock downgrade test Paolo Bonzini
2021-03-24 14:26 ` [PATCH v5 0/6] coroutine rwlock downgrade fix, minor VDI changes Max Reitz
2021-03-24 16:23 ` Stefan Hajnoczi
2021-03-24 16:43 ` Paolo Bonzini
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