From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <pbs-devel-bounces@lists.proxmox.com>
Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9])
by lore.proxmox.com (Postfix) with ESMTPS id 9951F1FF189
for <inbox@lore.proxmox.com>; Fri, 21 Mar 2025 10:32:12 +0100 (CET)
Received: from firstgate.proxmox.com (localhost [127.0.0.1])
by firstgate.proxmox.com (Proxmox) with ESMTP id 1E8DD1A291;
Fri, 21 Mar 2025 10:32:09 +0100 (CET)
From: Christian Ebner <c.ebner@proxmox.com>
To: pbs-devel@lists.proxmox.com
Date: Fri, 21 Mar 2025 10:32:02 +0100
Message-Id: <20250321093202.155899-6-c.ebner@proxmox.com>
X-Mailer: git-send-email 2.39.5
In-Reply-To: <20250321093202.155899-1-c.ebner@proxmox.com>
References: <20250321093202.155899-1-c.ebner@proxmox.com>
MIME-Version: 1.0
X-SPAM-LEVEL: Spam detection results: 0
AWL 0.030 Adjusted score from AWL reputation of From: address
BAYES_00 -1.9 Bayes spam probability is 0 to 1%
DMARC_MISSING 0.1 Missing DMARC policy
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: [pbs-devel] [PATCH v4 proxmox-backup 5/5] fix #5331: garbage
collection: avoid multiple chunk atime updates
X-BeenThere: pbs-devel@lists.proxmox.com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Proxmox Backup Server development discussion
<pbs-devel.lists.proxmox.com>
List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pbs-devel>,
<mailto:pbs-devel-request@lists.proxmox.com?subject=unsubscribe>
List-Archive: <http://lists.proxmox.com/pipermail/pbs-devel/>
List-Post: <mailto:pbs-devel@lists.proxmox.com>
List-Help: <mailto:pbs-devel-request@lists.proxmox.com?subject=help>
List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel>,
<mailto:pbs-devel-request@lists.proxmox.com?subject=subscribe>
Reply-To: Proxmox Backup Server development discussion
<pbs-devel@lists.proxmox.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: pbs-devel-bounces@lists.proxmox.com
Sender: "pbs-devel" <pbs-devel-bounces@lists.proxmox.com>
To reduce the number of atimes updates, keep track of the recently
marked chunks in phase 1 of garbage to avoid multiple atime updates
via expensive utimensat() calls.
Recently touched chunks are tracked by storing the chunk digests in
an LRU cache of fixed capacity. By inserting a digest, the chunk will
be the most recently touched one and if already present in the cache
before insert, the atime update can be skipped.
Fixes: https://bugzilla.proxmox.com/show_bug.cgi?id=5331
Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
---
changes since version 3:
- no changes
pbs-datastore/src/datastore.rs | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index ea7e5e9f3..4445944c0 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -7,6 +7,7 @@ use std::sync::{Arc, LazyLock, Mutex};
use anyhow::{bail, format_err, Context, Error};
use nix::unistd::{unlinkat, UnlinkatFlags};
+use pbs_tools::lru_cache::LruCache;
use tracing::{info, warn};
use proxmox_human_byte::HumanByte;
@@ -1078,6 +1079,7 @@ impl DataStore {
&self,
index: Box<dyn IndexFile>,
file_name: &Path, // only used for error reporting
+ recently_touched_chunks: &mut LruCache<[u8; 32], ()>,
status: &mut GarbageCollectionStatus,
worker: &dyn WorkerTaskContext,
) -> Result<(), Error> {
@@ -1088,6 +1090,12 @@ impl DataStore {
worker.check_abort()?;
worker.fail_on_shutdown()?;
let digest = index.index_digest(pos).unwrap();
+
+ // Avoid multiple expensive atime updates by utimensat
+ if recently_touched_chunks.insert(*digest, ()) {
+ continue;
+ }
+
if !self.inner.chunk_store.cond_touch_chunk(digest, false)? {
let hex = hex::encode(digest);
warn!(
@@ -1128,6 +1136,8 @@ impl DataStore {
let mut unprocessed_index_list = self.list_index_files()?;
let index_count = unprocessed_index_list.len();
+ // Allow up to 32 MiB, as only storing the 32 digest as key
+ let mut recently_touched_chunks = LruCache::new(1024 * 1024);
let mut processed_index_files = 0;
let mut last_percentage: usize = 0;
@@ -1154,7 +1164,13 @@ impl DataStore {
Some(index) => index,
None => continue,
};
- self.index_mark_used_chunks(index, &path, status, worker)?;
+ self.index_mark_used_chunks(
+ index,
+ &path,
+ &mut recently_touched_chunks,
+ status,
+ worker,
+ )?;
unprocessed_index_list.remove(&path);
@@ -1181,7 +1197,13 @@ impl DataStore {
Some(index) => index,
None => continue,
};
- self.index_mark_used_chunks(index, &path, status, worker)?;
+ self.index_mark_used_chunks(
+ index,
+ &path,
+ &mut recently_touched_chunks,
+ status,
+ worker,
+ )?;
warn!("Marked chunks for unexpected index file at '{path:?}'");
}
--
2.39.5
_______________________________________________
pbs-devel mailing list
pbs-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel