From: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
To: Tony Luck <tony.luck@gmail.com>
Cc: "linuxppc-dev@ozlabs.org" <linuxppc-dev@ozlabs.org>,
"paulus@samba.org" <paulus@samba.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"keescook@chromium.org" <keescook@chromium.org>
Subject: Re: [PATCH 00/11] Add compression support to pstore
Date: Thu, 08 Aug 2013 09:59:34 +0530 [thread overview]
Message-ID: <52031EAE.5080005@linux.vnet.ibm.com> (raw)
In-Reply-To: <CA+8MBb+dNkT_xpqL6oy=D3UqCtEwAci5fatw-0crCFLMAGE1nA@mail.gmail.com>
On Wednesday 07 August 2013 11:00 PM, Tony Luck wrote:
> Oh - one more thing - and my apologies for not spotting this before:
>
> dst = allocate_buf_for_compression(big_buf_sz);
>
> No - you may not call kmalloc() in oops/panic context. Please pre-allocate
> everything you need in some initialization code to make sure that we don't
> fail in the panic path because we can't get the memory we need.
>
> -Tony
Sure. I had this in mind. At the same time memory consumed for compression is
quite high.
For the compression parameters used, workspace will be 30k and big_buf will be 17.5k
for the record size of 7896 that you have mentioned.
So total memory consumed for compression and decompression will close 47.5k.
When we preallocate, we can use the same big_buf for compression as well as
decompression.
Also workspace will be one for both. By allocating max of inflate workspace size
and deflate
workspace size. We can save memory here.
If pre-allocating close to 50k of buffer is not a issue. We can go ahead with
this approach.
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>
next prev parent reply other threads:[~2013-08-08 4:29 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-15 16:55 [PATCH 00/11] Add compression support to pstore Aruna Balakrishnaiah
2013-07-15 16:55 ` [PATCH 01/11] powerpc/pseries: Remove (de)compression in nvram with pstore enabled Aruna Balakrishnaiah
2013-07-15 16:55 ` [PATCH 02/11] pstore: Add new argument 'compressed' in pstore write callback Aruna Balakrishnaiah
2013-07-15 16:55 ` [PATCH 03/11] pstore/Kconfig: Select ZLIB_DEFLATE and ZLIB_INFLATE when PSTORE is selected Aruna Balakrishnaiah
2013-07-15 16:55 ` [PATCH 04/11] pstore: Add compression support to pstore Aruna Balakrishnaiah
2013-07-15 16:55 ` [PATCH 05/11] pstore: Introduce new argument 'compressed' in the read callback Aruna Balakrishnaiah
2013-07-15 16:56 ` [PATCH 06/11] pstore: Provide decompression support to pstore Aruna Balakrishnaiah
2013-07-15 16:56 ` [PATCH 07/11] pstore: Add file extension to pstore file if compressed Aruna Balakrishnaiah
2013-07-15 16:56 ` [PATCH 08/11] powerpc/pseries: Read and write to the 'compressed' flag of pstore Aruna Balakrishnaiah
2013-07-15 16:56 ` [PATCH 09/11] erst: " Aruna Balakrishnaiah
2013-07-15 16:56 ` [PATCH 10/11] efi-pstore: " Aruna Balakrishnaiah
2013-07-15 16:57 ` [PATCH 11/11] pstore/ram: " Aruna Balakrishnaiah
2013-08-01 10:40 ` [PATCH 00/11] Add compression support to pstore Aruna Balakrishnaiah
2013-08-01 23:42 ` Luck, Tony
2013-08-02 21:39 ` Tony Luck
2013-08-02 22:12 ` Tony Luck
2013-08-05 16:41 ` Tony Luck
2013-08-05 17:10 ` Aruna Balakrishnaiah
2013-08-05 18:22 ` Tony Luck
2013-08-05 19:41 ` Aruna Balakrishnaiah
2013-08-05 21:20 ` Tony Luck
2013-08-06 23:36 ` Tony Luck
2013-08-07 1:58 ` Aruna Balakrishnaiah
2013-08-07 3:25 ` Tony Luck
2013-08-07 5:13 ` Aruna Balakrishnaiah
2013-08-07 5:35 ` Tony Luck
2013-08-07 17:30 ` Tony Luck
2013-08-08 4:29 ` Aruna Balakrishnaiah [this message]
2013-08-08 5:05 ` Tony Luck
2013-08-07 22:22 ` Tony Luck
2013-08-08 4:08 ` Aruna Balakrishnaiah
2013-08-09 10:13 ` Aruna Balakrishnaiah
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