From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id BE52A70611; Mon, 7 Jun 2021 10:08:50 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id ACF85E4D0; Mon, 7 Jun 2021 10:08:50 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id D8CC4E4C2; Mon, 7 Jun 2021 10:08:46 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id A8B9642933; Mon, 7 Jun 2021 10:08:46 +0200 (CEST) Date: Mon, 7 Jun 2021 10:07:59 +0200 (CEST) From: Wolfgang Bumiller To: Stefan Reiter Cc: pve-devel@lists.proxmox.com, pbs-devel@lists.proxmox.com Message-ID: <718212628.349.1623053279055@webmail.proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Priority: 3 Importance: Normal X-Mailer: Open-Xchange Mailer v7.10.5-Rev13 X-Originating-Client: open-xchange-appsuite X-SPAM-LEVEL: Spam detection results: 0 AWL 0.966 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [pbs-devel] [PATCH proxmox-backup-qemu 8/9] add shared_cache module X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Jun 2021 08:08:50 -0000 > On 06/07/2021 10:03 AM Stefan Reiter wrote: > > > On 6/4/21 2:16 PM, Wolfgang Bumiller wrote: > > On Wed, Jun 02, 2021 at 04:38:32PM +0200, Stefan Reiter wrote: > >> Provides a shared AsyncLruCache of 256MB (w/ 4MB chunks) that can be > >> used by multiple readers at the same time. It is dropped once no more > >> readers exist, so the memory gets freed if all QEMU block/pbs instances > >> disappear. > >> > >> Signed-off-by: Stefan Reiter > >> --- > >> src/lib.rs | 7 ++++++- > >> src/shared_cache.rs | 36 ++++++++++++++++++++++++++++++++++++ > >> 2 files changed, 42 insertions(+), 1 deletion(-) > >> create mode 100644 src/shared_cache.rs > >> > >> diff --git a/src/lib.rs b/src/lib.rs > >> index 05d7b58..aa167f7 100644 > >> --- a/src/lib.rs > >> +++ b/src/lib.rs > >> @@ -25,6 +25,7 @@ mod restore; > >> use restore::*; > >> > >> mod tools; > >> +mod shared_cache; > >> > >> pub const PROXMOX_BACKUP_DEFAULT_CHUNK_SIZE: u64 = 1024*1024*4; > >> > >> @@ -804,7 +805,11 @@ pub extern "C" fn proxmox_restore_connect_async( > >> pub extern "C" fn proxmox_restore_disconnect(handle: *mut ProxmoxRestoreHandle) { > >> > >> let restore_task = handle as * mut Arc; > >> - unsafe { Box::from_raw(restore_task) }; //drop(restore_task) > >> + let restore_task = unsafe { Box::from_raw(restore_task) }; > >> + drop(restore_task); > >> + > >> + // after dropping, cache may be unused (if no other handles open) > >> + shared_cache::shared_chunk_cache_cleanup(); > >> } > >> > >> /// Restore an image (sync) > >> diff --git a/src/shared_cache.rs b/src/shared_cache.rs > >> new file mode 100644 > >> index 0000000..bebae5b > >> --- /dev/null > >> +++ b/src/shared_cache.rs > >> @@ -0,0 +1,36 @@ > >> +use once_cell::sync::OnceCell; > >> +use proxmox_backup::backup::ChunkCache; > >> +use proxmox_backup::tools::async_lru_cache::AsyncLruCache; > >> +use std::sync::{Arc, Mutex}; > >> + > >> +const SHARED_CACHE_CAPACITY: usize = 64; // 256 MB > >> +static SHARED_CACHE: OnceCell>> = OnceCell::new(); > > > > OnceCell *and* Option is a bit too much, `get_shared_chunk_chache()` can > > just initialize it in `get_or_init()` directly. > > > > Then how do we drop the ChunkCache? I used OnceCell since > std::sync::Mutex doesn't seem to have a 'const new', not because of > 'Option' semantics. Right. I forgot about the cleanup. As for the const Mutex::new... don't we have parking lot in our dependency tree already? ;-) But yeah, I guess it's fine.