From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: chengming.zhou@linux.dev
Cc: minchan@kernel.org, senozhatsky@chromium.org,
akpm@linux-foundation.org, hannes@cmpxchg.org, nphamcs@gmail.com,
yosryahmed@google.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Chengming Zhou <zhouchengming@bytedance.com>
Subject: Re: [PATCH] mm/zsmalloc: don't need to save tag bit in handle
Date: Tue, 27 Feb 2024 16:52:09 +0900 [thread overview]
Message-ID: <20240227075209.GA11972@google.com> (raw)
In-Reply-To: <20240227030045.3443702-1-chengming.zhou@linux.dev>
On (24/02/27 03:00), chengming.zhou@linux.dev wrote:
>
> We only need to save the position (pfn + obj_idx) in the handle, don't
> need to save tag bit in handle. So one more bit can be used as obj_idx.
[..]
> mm/zsmalloc: don't need to save tag bit in handle
Does this mean "don't need to reserve LSB for tag"?
We still save allocated tag in the handle, that's what
handle |= OBJ_ALLOCATED_TAG;
does.
> Actually, the tag bit is only useful in zspage's memory space, to tell
> if an object is allocated or not.
I'm not completely sure if I follow this sentence.
next prev parent reply other threads:[~2024-02-27 7:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-27 3:00 [PATCH] mm/zsmalloc: don't need to save tag bit in handle chengming.zhou
2024-02-27 7:52 ` Sergey Senozhatsky [this message]
2024-02-27 8:16 ` Chengming Zhou
2024-02-28 1:54 ` Sergey Senozhatsky
2024-02-28 2:17 ` Chengming Zhou
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