linux-kernel - Re: [PATCH v4] binder_alloc: Replace kcalloc with kvcalloc to mitigate OOM issues

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Date: Wed, 19 Jun 2024 23:44:09 +0000
From: Carlos Llamas <cmllamas@...gle.com>
To: Lei Liu <liulei.rjpt@...o.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Arve Hjønnevåg <arve@...roid.com>,
	Todd Kjos <tkjos@...roid.com>, Martijn Coenen <maco@...roid.com>,
	Joel Fernandes <joel@...lfernandes.org>,
	Christian Brauner <brauner@...nel.org>,
	Suren Baghdasaryan <surenb@...gle.com>,
	linux-kernel@...r.kernel.org, opensource.kernel@...o.com
Subject: Re: [PATCH v4] binder_alloc: Replace kcalloc with kvcalloc to
 mitigate OOM issues

On Wed, Jun 19, 2024 at 07:38:40PM +0800, Lei Liu wrote:
> In binder_alloc, there is a frequent need for order3 memory allocation,
> especially on small-memory mobile devices, which can lead to OOM and
> cause foreground applications to be killed, resulting in flashbacks.
> 
> We use kvcalloc to allocate memory, which can reduce system OOM
> occurrences, as well as decrease the time and probability of failure for
> order3 memory allocations. Additionally, It has little impact on the
> throughput of the binder. (as verified by Google's binder_benchmark
> testing tool).
> 
> We have conducted multiple tests on an 8GB memory phone, kvcalloc has
> little performance degradation and resolves frequent OOM issues, Below
> is a partial excerpt of the test data.
> 
> throughput(TH_PUT) = (size * Iterations)/Time
> kcalloc->kvcalloc:
> 
> Sample with kcalloc():
> adb shell stop/ kcalloc /8+256G
> ---------------------------------------------------------------------
> Benchmark                Time     CPU   Iterations  TH-PUT  TH-PUTCPU
>                          (ns)     (ns)              (GB/s)    (GB/s)
> ---------------------------------------------------------------------
> BM_sendVec_binder4      39126    18550    38894    3.976282  8.38684
> BM_sendVec_binder8      38924    18542    37786    7.766108  16.3028
> BM_sendVec_binder16     38328    18228    36700    15.32039  32.2141
> BM_sendVec_binder32     38154    18215    38240    32.07213  67.1798
> BM_sendVec_binder64     39093    18809    36142    59.16885  122.977
> BM_sendVec_binder128    40169    19188    36461    116.1843  243.2253
> BM_sendVec_binder256    40695    19559    35951    226.1569  470.5484
> BM_sendVec_binder512    41446    20211    34259    423.2159  867.8743
> BM_sendVec_binder1024   44040    22939    28904    672.0639  1290.278
> BM_sendVec_binder2048   47817    25821    26595    1139.063  2109.393
> BM_sendVec_binder4096   54749    30905    22742    1701.423  3014.115
> BM_sendVec_binder8192   68316    42017    16684    2000.634  3252.858
> BM_sendVec_binder16384  95435    64081    10961    1881.752  2802.469
> BM_sendVec_binder32768  148232  107504     6510    1439.093  1984.295
> BM_sendVec_binder65536  326499  229874     3178    637.8991  906.0329
> NORAML TEST                                 SUM    10355.79  17188.15
> stressapptest eat 2G                        SUM    10088.39  16625.97
> 
> Sample with kvcalloc():
> adb shell stop/ kvcalloc /8+256G
> ----------------------------------------------------------------------
> Benchmark                Time     CPU   Iterations  TH-PUT  TH-PUTCPU
>                          (ns)     (ns)              (GB/s)    (GB/s)
> ----------------------------------------------------------------------
> BM_sendVec_binder4       39673    18832    36598    3.689965  7.773577
> BM_sendVec_binder8       39869    18969    37188    7.462038  15.68369
> BM_sendVec_binder16      39774    18896    36627    14.73405  31.01355
> BM_sendVec_binder32      40225    19125    36995    29.43045  61.90013
> BM_sendVec_binder64      40549    19529    35148    55.47544  115.1862
> BM_sendVec_binder128     41580    19892    35384    108.9262  227.6871
> BM_sendVec_binder256     41584    20059    34060    209.6806  434.6857
> BM_sendVec_binder512     42829    20899    32493    388.4381  796.0389
> BM_sendVec_binder1024    45037    23360    29251    665.0759  1282.236
> BM_sendVec_binder2048    47853    25761    27091    1159.433  2153.735
> BM_sendVec_binder4096    55574    31745    22405    1651.328  2890.877
> BM_sendVec_binder8192    70706    43693    16400    1900.105  3074.836
> BM_sendVec_binder16384   96161    64362    10793    1838.921  2747.468
> BM_sendVec_binder32768  147875   107292     6296    1395.147  1922.858
> BM_sendVec_binder65536  330324   232296     3053    605.7126  861.3209
> NORAML TEST                                 SUM     10033.56  16623.35
> stressapptest eat 2G                        SUM      9958.43  16497.55
> 
> Signed-off-by: Lei Liu <liulei.rjpt@...o.com>
> 
> ---

This looks great, thanks for the hard work!

Acked-by: Carlos Llamas <cmllamas@...gle.com>