From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Joonsoo Kim <js1304@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Minchan Kim <minchan@kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [RFC PATCH 3/3] mm/zsmalloc: change ZS_MAX_PAGES_PER_ZSPAGE
Date: Fri, 19 Feb 2016 14:55:07 +0900 [thread overview]
Message-ID: <20160219055507.GC16230@swordfish> (raw)
In-Reply-To: <20160219053814.GB16230@swordfish>
On (02/19/16 14:38), Sergey Senozhatsky wrote:
[..]
> #define OBJ_ALLOCATED_TAG 1
> #define OBJ_TAG_BITS 1
> #define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS)
> #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)
>
> #define ZS_MIN_ALLOC_SIZE \
> MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
[..]
> -- on 32 bit system, PAGE_SHIFT 12
>
> ZS_MAX_PAGES_PER_ZSPAGE 1 << 4 16
> OBJ_INDEX_BITS (32 - (32 - 12) - 1) 11
> OBJ_INDEX_MASK ((1 << (32 - (32 - 12) - 1)) - 1) 2047
> ZS_MIN_ALLOC_SIZE MAX(32, ((1 << 4) << 12 >> (32 - (32 - 12) - 1))) 32
>
> -- on 64 bit system, PAGE_SHIFT 12
>
> ZS_MAX_PAGES_PER_ZSPAGE 1 << 4 16
> OBJ_INDEX_BITS (64 - (64 - 12) - 1) 11
> OBJ_INDEX_MASK ((1 << (64 - (64 - 12) - 1)) - 1) 2047
> ZS_MIN_ALLOC_SIZE MAX(32, ((1 << 4) << 12 >> (64 - (64 - 12) - 1))) 32
even if it's missing "HANDLE_PIN_BIT 0", it's still OBJ_INDEX_BITS 10,
2<<10 should be enough to keep 32 bytes class around.
> -- on 64 bit system, PAGE_SHIFT 14
>
> ZS_MAX_PAGES_PER_ZSPAGE 1 << 4 16
> OBJ_INDEX_BITS (64 - (64 - 14) - 1) 13
> OBJ_INDEX_MASK ((1 << (64 - (64 - 14) - 1)) - 1) 8191
> ZS_MIN_ALLOC_SIZE MAX(32, ((1 << 4) << 14 >> (64 - (64 - 14) - 1))) 32
OBJ_INDEX_BITS 2<<12 still looks to be good enough.
-ss
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Joonsoo Kim <js1304@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Minchan Kim <minchan@kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [RFC PATCH 3/3] mm/zsmalloc: change ZS_MAX_PAGES_PER_ZSPAGE
Date: Fri, 19 Feb 2016 14:55:07 +0900 [thread overview]
Message-ID: <20160219055507.GC16230@swordfish> (raw)
In-Reply-To: <20160219053814.GB16230@swordfish>
On (02/19/16 14:38), Sergey Senozhatsky wrote:
[..]
> #define OBJ_ALLOCATED_TAG 1
> #define OBJ_TAG_BITS 1
> #define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS)
> #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)
>
> #define ZS_MIN_ALLOC_SIZE \
> MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
[..]
> -- on 32 bit system, PAGE_SHIFT 12
>
> ZS_MAX_PAGES_PER_ZSPAGE 1 << 4 16
> OBJ_INDEX_BITS (32 - (32 - 12) - 1) 11
> OBJ_INDEX_MASK ((1 << (32 - (32 - 12) - 1)) - 1) 2047
> ZS_MIN_ALLOC_SIZE MAX(32, ((1 << 4) << 12 >> (32 - (32 - 12) - 1))) 32
>
> -- on 64 bit system, PAGE_SHIFT 12
>
> ZS_MAX_PAGES_PER_ZSPAGE 1 << 4 16
> OBJ_INDEX_BITS (64 - (64 - 12) - 1) 11
> OBJ_INDEX_MASK ((1 << (64 - (64 - 12) - 1)) - 1) 2047
> ZS_MIN_ALLOC_SIZE MAX(32, ((1 << 4) << 12 >> (64 - (64 - 12) - 1))) 32
even if it's missing "HANDLE_PIN_BIT 0", it's still OBJ_INDEX_BITS 10,
2<<10 should be enough to keep 32 bytes class around.
> -- on 64 bit system, PAGE_SHIFT 14
>
> ZS_MAX_PAGES_PER_ZSPAGE 1 << 4 16
> OBJ_INDEX_BITS (64 - (64 - 14) - 1) 13
> OBJ_INDEX_MASK ((1 << (64 - (64 - 14) - 1)) - 1) 8191
> ZS_MIN_ALLOC_SIZE MAX(32, ((1 << 4) << 14 >> (64 - (64 - 14) - 1))) 32
OBJ_INDEX_BITS 2<<12 still looks to be good enough.
-ss
next prev parent reply other threads:[~2016-02-19 5:53 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-18 3:02 [RFC PATCH 0/3] mm/zsmalloc: increase density and reduce memory wastage Sergey Senozhatsky
2016-02-18 3:02 ` Sergey Senozhatsky
2016-02-18 3:02 ` [RFC PATCH 1/3] mm/zsmalloc: introduce zs_get_huge_class_size_watermark() Sergey Senozhatsky
2016-02-18 3:02 ` Sergey Senozhatsky
2016-02-18 3:02 ` [RFC PATCH 2/3] zram: use zs_get_huge_class_size_watermark() Sergey Senozhatsky
2016-02-18 3:02 ` Sergey Senozhatsky
2016-02-18 3:02 ` [RFC PATCH 3/3] mm/zsmalloc: change ZS_MAX_PAGES_PER_ZSPAGE Sergey Senozhatsky
2016-02-18 3:02 ` Sergey Senozhatsky
2016-02-18 4:41 ` Sergey Senozhatsky
2016-02-18 4:41 ` Sergey Senozhatsky
2016-02-18 4:46 ` Sergey Senozhatsky
2016-02-18 4:46 ` Sergey Senozhatsky
2016-02-18 5:03 ` Sergey Senozhatsky
2016-02-18 5:03 ` Sergey Senozhatsky
2016-02-18 8:28 ` Joonsoo Kim
2016-02-18 8:28 ` Joonsoo Kim
2016-02-18 9:55 ` Sergey Senozhatsky
2016-02-18 9:55 ` Sergey Senozhatsky
2016-02-18 10:19 ` Sergey Senozhatsky
2016-02-18 10:19 ` Sergey Senozhatsky
2016-02-19 1:19 ` Joonsoo Kim
2016-02-19 1:19 ` Joonsoo Kim
2016-02-19 4:16 ` Sergey Senozhatsky
2016-02-19 4:16 ` Sergey Senozhatsky
2016-02-19 4:19 ` Sergey Senozhatsky
2016-02-19 4:19 ` Sergey Senozhatsky
2016-02-19 4:46 ` Sergey Senozhatsky
2016-02-19 4:46 ` Sergey Senozhatsky
2016-02-19 5:38 ` Sergey Senozhatsky
2016-02-19 5:38 ` Sergey Senozhatsky
2016-02-19 5:55 ` Sergey Senozhatsky [this message]
2016-02-19 5:55 ` Sergey Senozhatsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160219055507.GC16230@swordfish \
--to=sergey.senozhatsky.work@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=js1304@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan@kernel.org \
--cc=sergey.senozhatsky@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.