From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: zhangdongdong <zhangdongdong925@sina.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Richard Chang <richardycc@google.com>,
Minchan Kim <minchan@kernel.org>,
Brian Geffon <bgeffon@google.com>,
David Stevens <stevensd@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-block@vger.kernel.org, Minchan Kim <minchan@google.com>
Subject: Re: [PATCHv2 1/7] zram: introduce compressed data writeback
Date: Wed, 7 Jan 2026 13:28:11 +0900 [thread overview]
Message-ID: <7bnmkuodymm33yclp6e5oir2sqnqmpwlsb5qlxqyawszb5bvlu@l63wu3ckqihc> (raw)
In-Reply-To: <40e38fa7-725b-407a-917a-59c5a76dedcb@sina.com>
On (26/01/07 11:50), zhangdongdong wrote:
> Hi Sergey,
>
> Thanks for the work on decompression-on-demand.
>
> One concern I’d like to raise is the use of a workqueue for readback
> decompression. In our measurements, deferring decompression to a worker
> introduces non-trivial scheduling overhead, and under memory pressure
> the added latency can be noticeable (tens of milliseconds in some cases).
The problem is those bio completions happen in atomic context, and zram
requires both compression and decompression to be non-atomic. And we
can't do sync read on the zram side, because those bio-s are chained.
So the current plan is to look how system hi-prio per-cpu workqueue
will handle this.
Did you try high priority workqueue?
next prev parent reply other threads:[~2026-01-07 4:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-01 9:47 [PATCHv2 0/7] " Sergey Senozhatsky
2025-12-01 9:47 ` [PATCHv2 1/7] " Sergey Senozhatsky
2026-01-07 3:50 ` zhangdongdong
2026-01-07 4:28 ` Sergey Senozhatsky [this message]
2026-01-07 7:28 ` zhangdongdong
2026-01-07 10:14 ` Sergey Senozhatsky
2026-01-08 2:57 ` zhangdongdong
2026-01-08 3:39 ` Sergey Senozhatsky
2026-01-08 10:36 ` zhangdongdong
2025-12-01 9:47 ` [PATCHv2 2/7] zram: introduce writeback_compressed device attribute Sergey Senozhatsky
2025-12-01 9:47 ` [PATCHv2 3/7] zram: document writeback_batch_size Sergey Senozhatsky
2025-12-01 9:47 ` [PATCHv2 4/7] zram: move bd_stat to writeback section Sergey Senozhatsky
2025-12-01 9:47 ` [PATCHv2 5/7] zram: rename zram_free_page() Sergey Senozhatsky
2025-12-01 9:47 ` [PATCHv2 6/7] zram: switch to guard() for init_lock Sergey Senozhatsky
2025-12-01 9:47 ` [PATCHv2 7/7] zram: consolidate device-attr declarations Sergey Senozhatsky
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