From: Kevin Wolf <kwolf@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [RFC PATCH 15/16] qcow2: Cancel COW when overwritten
Date: Tue, 18 Sep 2012 17:02:58 +0200 [thread overview]
Message-ID: <50588D22.6080703@redhat.com> (raw)
In-Reply-To: <505888CC.8070207@redhat.com>
Am 18.09.2012 16:44, schrieb Paolo Bonzini:
> Il 18/09/2012 13:40, Kevin Wolf ha scritto:
>> + qemu_co_mutex_unlock(&s->lock);
>> + qemu_co_rwlock_wrlock(&m->l2_writeback_lock);
>
> Can anybody else take the lock as reader again at this point? If not, I
> wonder if this is more clear if you write it as a CoQueue.
This isn't "let one writer complete, then wake up n readers" (which
would indeed be represented more naturally as CoQueue), but rather "let
n readers complete, then wake up one writer".
Kevin
next prev parent reply other threads:[~2012-09-18 15:03 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-18 11:40 [Qemu-devel] [RFC PATCH 00/16] qcow2: Delayed COW Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 01/16] qcow2: Round QCowL2Meta.offset down to cluster boundary Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 02/16] qcow2: Introduce Qcow2COWRegion Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 03/16] qcow2: Allocate l2meta dynamically Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 04/16] qcow2: Drop l2meta.cluster_offset Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 05/16] qcow2: Allocate l2meta only for cluster allocations Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 06/16] qcow2: Enable dirty flag in qcow2_alloc_cluster_link_l2 Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 07/16] qcow2: Factor out handle_dependencies() Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 08/16] qcow2: Reading from areas not in L2 tables yet Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 09/16] qcow2: Move COW and L2 update into own coroutine Kevin Wolf
2012-09-18 14:24 ` Paolo Bonzini
2012-09-18 14:44 ` Kevin Wolf
2012-09-18 14:59 ` Paolo Bonzini
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 10/16] qcow2: Delay the COW Kevin Wolf
2012-09-18 14:27 ` Paolo Bonzini
2012-09-18 14:49 ` Kevin Wolf
2012-09-19 18:47 ` Blue Swirl
2012-09-20 6:58 ` Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 11/16] qcow2: Add error handling to the l2meta coroutine Kevin Wolf
2012-09-18 14:29 ` Paolo Bonzini
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 12/16] qcow2: Handle dependencies earlier Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 13/16] qcow2: Change handle_dependency to byte granularity Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 14/16] qcow2: Execute run_dependent_requests() without lock Kevin Wolf
2012-09-18 14:33 ` Paolo Bonzini
2012-09-18 14:54 ` Kevin Wolf
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 15/16] qcow2: Cancel COW when overwritten Kevin Wolf
2012-09-18 14:44 ` Paolo Bonzini
2012-09-18 15:02 ` Kevin Wolf [this message]
2012-09-18 15:05 ` Paolo Bonzini
2012-09-18 15:08 ` Paolo Bonzini
2012-09-18 11:40 ` [Qemu-devel] [RFC PATCH 16/16] [BROKEN] qcow2: Overwrite COW and allocate new cluster at the same time Kevin Wolf
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