From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98868C33CA9 for ; Mon, 13 Jan 2020 18:02:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 58A9D21556 for ; Mon, 13 Jan 2020 18:02:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578938560; bh=TndULhFhWSUbawMN/PIiyi+KwjHkI1unXQ53EpVXsyM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=15UGlzs90ztYPySE3+3EjLjcqlWigpNzS3wfNa1UnJ3qiqvqqiOmjxWyv6svLGoYK lMEvOORcisiufQfGmw0HM4x/H8e4yKMGrpqj7p0FIyFcHrtk19H1LEOOHnf9en2AFc XtuxBoBJHlZDDp8kAOK7T0qiMsH46Arw9HAYdFVk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728794AbgAMSCj (ORCPT ); Mon, 13 Jan 2020 13:02:39 -0500 Received: from mail-pj1-f66.google.com ([209.85.216.66]:37350 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727726AbgAMSCj (ORCPT ); Mon, 13 Jan 2020 13:02:39 -0500 Received: by mail-pj1-f66.google.com with SMTP id m13so4604814pjb.2; Mon, 13 Jan 2020 10:02:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3LTw7gnh2l+GenASPNMgebGB+0QdjUuP2xkFIISEt1k=; b=SNvR1EqyZEkpVxwyZe+G9tvItFI6ANOEEsFwSzUdxfb6EQHtis4t8ScfhdKZ8W0hQU Ms1RN7pbPwvW63JV6jLfFoKNGSad7fUV9jWhJr8pipyGuITyR105XJummcDzd+4sIOFY sFvro+82OOPcEHSZo/5dw372DQUCReQyUAydtQ9zcqioUlhrS4aqh71KyqnOOnpVVZK3 e12i0+Wq/cwwvZEkmu185f5vCokVhFOkzEnPt2yGYG9kFUMgIOj3LbrEUrNCX41eNZHe uVTB8mbrzTIh/BJOGLF2N6HNl8zG/nu6p3oBH79h7cm5BEGELQxuS0oRZBGNbc4lXDCb k+cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=3LTw7gnh2l+GenASPNMgebGB+0QdjUuP2xkFIISEt1k=; b=V8QdU5a7yWJ3KIiBF6FwqMl/y/ZxRptIz/6O8hZ1tiu9FZydqzJH7EUB0xUAPECcwP wFmZ857Bp/hJIprlRuu8P/VIdlriRf2iV1TqGQnVstyEGEdKMBGF87XOJbriufpLPYZ/ fRo72LLCQCOVNBQ3lQUd1Bgl2hWii77RRXG40Be9Lm9QBa/7UM3jIJyZXVbu5QHbH17L sJNw9A2elPJiLdtTRV9/rl2ureLg6ZWyTUjAkrzMah74EKmp8AVQycx/O4WMtbbpXRLw 41lv7Bqilf+m5z1XivNukgw5e7XnHjFhrHyDdcdI7hvczywPj3Xhw7q3lfec2523YkZo z7mg== X-Gm-Message-State: APjAAAVo/fHy3zhlPsOPApSUKV+ZvbHk3qyGQNCA+JkrNO+shWrX8wxP c2OEEf1LQdWZHROU30ICj8U= X-Google-Smtp-Source: APXvYqwtKvDz8srJ5hh5IFVAaDmTKCmCFhbN78Ba2LDKf1eZOgWMK7Hgjh67AG3vsmBcrmeNw/yBXg== X-Received: by 2002:a17:90a:35e6:: with SMTP id r93mr23723158pjb.44.1578938557564; Mon, 13 Jan 2020 10:02:37 -0800 (PST) Received: from google.com ([2620:15c:211:1:3e01:2939:5992:52da]) by smtp.gmail.com with ESMTPSA id t30sm14096286pgl.75.2020.01.13.10.02.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jan 2020 10:02:33 -0800 (PST) Date: Mon, 13 Jan 2020 10:02:30 -0800 From: Minchan Kim To: SeongJae Park Cc: Andrew Morton , LKML , linux-mm , linux-api@vger.kernel.org, oleksandr@redhat.com, Suren Baghdasaryan , Tim Murray , Daniel Colascione , Sandeep Patil , Sonny Rao , Brian Geffon , Michal Hocko , Johannes Weiner , Shakeel Butt , John Dias Subject: Re: [PATCH 2/4] mm: introduce external memory hinting API Message-ID: <20200113180230.GA110363@google.com> References: <20200110213433.94739-3-minchan@kernel.org> <20200111073452.25182-1-sj38.park@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200111073452.25182-1-sj38.park@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 11, 2020 at 08:34:52AM +0100, SeongJae Park wrote: > On Fri, 10 Jan 2020 13:34:31 -0800 Minchan Kim wrote: > > > There are usecases that System Management Software(SMS) want to give > > a memory hint to other processes because it's not known to the > > application. In the case of Android, ActivityManagerService daemon > > manges app's life cycle and that daemon must be able to initiate > > reclaim on its own without any app involvement. > > > > To solve the issue, this patch introduces new syscall process_madvise(2). > > It uses pidfd of an external processs to give the hint. > > > > int process_madvise(int pidfd, void *addr, size_t length, int advise, > > unsigned long flag); > > > > Since it could affect other process's address range, only privileged > > process(CAP_SYS_PTRACE) or something else(e.g., being the same UID) > > gives it the right to ptrace the process could use it successfully. > > The flag argument is reserved for future use if we need to extend the > > API. > > > > Supporting all hints madvise has/will supported/support to process_madvise > > is rather risky. Because we are not sure all hints make sense from external > > process and implementation for the hint may rely on the caller being > > in the current context so it could be error-prone. Thus, I just limited > > hints as MADV_[COLD|PAGEOUT] in this patch. > > > > If someone want to add other hints, we could hear hear the usecase and > > review it for each hint. It's more safe for maintainace rather than > > introducing a buggy syscall but hard to fix it later. > > > > Signed-off-by: Minchan Kim > > --- > > arch/alpha/kernel/syscalls/syscall.tbl | 1 + > > arch/arm/tools/syscall.tbl | 1 + > > arch/arm64/include/asm/unistd.h | 2 +- > > arch/arm64/include/asm/unistd32.h | 2 + > > arch/ia64/kernel/syscalls/syscall.tbl | 1 + > > arch/m68k/kernel/syscalls/syscall.tbl | 1 + > > arch/microblaze/kernel/syscalls/syscall.tbl | 1 + > > arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + > > arch/mips/kernel/syscalls/syscall_n64.tbl | 1 + > > arch/parisc/kernel/syscalls/syscall.tbl | 1 + > > arch/powerpc/kernel/syscalls/syscall.tbl | 1 + > > arch/s390/kernel/syscalls/syscall.tbl | 1 + > > arch/sh/kernel/syscalls/syscall.tbl | 1 + > > arch/sparc/kernel/syscalls/syscall.tbl | 1 + > > arch/x86/entry/syscalls/syscall_32.tbl | 1 + > > arch/x86/entry/syscalls/syscall_64.tbl | 1 + > > arch/xtensa/kernel/syscalls/syscall.tbl | 1 + > > include/linux/syscalls.h | 2 + > > include/uapi/asm-generic/unistd.h | 5 +- > > kernel/sys_ni.c | 1 + > > mm/madvise.c | 64 +++++++++++++++++++++ > > 21 files changed, 89 insertions(+), 2 deletions(-) > > > > diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl > > index e56950f23b49..776c61803315 100644 > > --- a/arch/alpha/kernel/syscalls/syscall.tbl > > +++ b/arch/alpha/kernel/syscalls/syscall.tbl > > @@ -477,3 +477,4 @@ > > # 545 reserved for clone3 > > 546 common watch_devices sys_watch_devices > > 547 common openat2 sys_openat2 > > +548 common process_madvise sys_process_madvise > > diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl > > index 7fb2f4d59210..a43381542276 100644 > > --- a/arch/arm/tools/syscall.tbl > > +++ b/arch/arm/tools/syscall.tbl > > @@ -451,3 +451,4 @@ > > 435 common clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h > > index 8aa00ccb0b96..b722e47377a5 100644 > > --- a/arch/arm64/include/asm/unistd.h > > +++ b/arch/arm64/include/asm/unistd.h > > @@ -38,7 +38,7 @@ > > #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) > > #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) > > > > -#define __NR_compat_syscalls 438 > > +#define __NR_compat_syscalls 439 > > #endif > > > > #define __ARCH_WANT_SYS_CLONE > > diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h > > index 31f0ce25719e..5c82557d408f 100644 > > --- a/arch/arm64/include/asm/unistd32.h > > +++ b/arch/arm64/include/asm/unistd32.h > > @@ -883,6 +883,8 @@ __SYSCALL(__NR_clone3, sys_clone3) > > __SYSCALL(__NR_watch_devices, sys_watch_devices) > > #define __NR_openat2 437 > > __SYSCALL(__NR_openat2, sys_openat2) > > +#define __NR_openat2 438 > > Shouldn't this be '#define __NR_process_madvise 438'? > > > +__SYSCALL(__NR_process_madvise, process_madvise) > > > > /* > > * Please add new compat syscalls above this comment and update > > diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl > > index b9aa59931905..c156abc9a298 100644 > > --- a/arch/ia64/kernel/syscalls/syscall.tbl > > +++ b/arch/ia64/kernel/syscalls/syscall.tbl > > @@ -358,3 +358,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl > > index 868c1ef89d35..5b6034b6650f 100644 > > --- a/arch/m68k/kernel/syscalls/syscall.tbl > > +++ b/arch/m68k/kernel/syscalls/syscall.tbl > > @@ -437,3 +437,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl > > index 544b4cef18b3..4bef584af09c 100644 > > --- a/arch/microblaze/kernel/syscalls/syscall.tbl > > +++ b/arch/microblaze/kernel/syscalls/syscall.tbl > > @@ -443,3 +443,4 @@ > > 435 common clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl > > index 05e8aee5dae7..94fbd0fcccce 100644 > > --- a/arch/mips/kernel/syscalls/syscall_n32.tbl > > +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl > > @@ -376,3 +376,4 @@ > > 435 n32 clone3 __sys_clone3 > > 436 n32 watch_devices sys_watch_devices > > 437 n32 openat2 sys_openat2 > > +437 n32 process_madivse sys_process_madvise > > Shouldn't the number for the 'process_madvise' be '438' instead of '437'? > > > diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl > > index 24d6c01328fb..4e6982c429d5 100644 > > --- a/arch/mips/kernel/syscalls/syscall_n64.tbl > > +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl > > @@ -352,3 +352,4 @@ > > 435 n64 clone3 __sys_clone3 > > 436 n64 watch_devices sys_watch_devices > > 437 n64 openat2 sys_openat2 > > +437 n64 process_madvise sys_process_madvise > > 438? Same for below 5 changes. > > > diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl > > index 4b5f77a4e1a2..3aa990caf9dc 100644 > > --- a/arch/parisc/kernel/syscalls/syscall.tbl > > +++ b/arch/parisc/kernel/syscalls/syscall.tbl > > @@ -435,3 +435,4 @@ > > 435 common clone3 sys_clone3_wrapper > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl > > index 9716dc85a517..30e727a23f33 100644 > > --- a/arch/powerpc/kernel/syscalls/syscall.tbl > > +++ b/arch/powerpc/kernel/syscalls/syscall.tbl > > @@ -519,3 +519,4 @@ > > 435 nospu clone3 ppc_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl > > index 7da330f8b03e..75722e5ff496 100644 > > --- a/arch/s390/kernel/syscalls/syscall.tbl > > +++ b/arch/s390/kernel/syscalls/syscall.tbl > > @@ -440,3 +440,4 @@ > > 435 common clone3 sys_clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise sys_process_madvise > > diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl > > index bb7e68e25337..7d7bc7befad3 100644 > > --- a/arch/sh/kernel/syscalls/syscall.tbl > > +++ b/arch/sh/kernel/syscalls/syscall.tbl > > @@ -440,3 +440,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl > > index 646a1fad7218..581d331ff62f 100644 > > --- a/arch/sparc/kernel/syscalls/syscall.tbl > > +++ b/arch/sparc/kernel/syscalls/syscall.tbl > > @@ -483,3 +483,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl > > index 57c53acee290..76a2c266fe7e 100644 > > --- a/arch/x86/entry/syscalls/syscall_32.tbl > > +++ b/arch/x86/entry/syscalls/syscall_32.tbl > > @@ -442,3 +442,4 @@ > > 435 i386 clone3 sys_clone3 __ia32_sys_clone3 > > 436 i386 watch_devices sys_watch_devices __ia32_sys_watch_devices > > 437 i386 openat2 sys_openat2 __ia32_sys_openat2 > > +438 i386 process_madvise sys_process_madvise __ia32_sys_process_madvise > > diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl > > index 1dd8d21f6500..b697cd8620cb 100644 > > --- a/arch/x86/entry/syscalls/syscall_64.tbl > > +++ b/arch/x86/entry/syscalls/syscall_64.tbl > > @@ -359,6 +359,7 @@ > > 435 common clone3 __x64_sys_clone3/ptregs > > 436 common watch_devices __x64_sys_watch_devices > > 437 common openat2 __x64_sys_openat2 > > +438 common process_madvise __x64_sys_process_madvise > > > > # > > # x32-specific system call numbers start at 512 to avoid cache impact > > diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl > > index 0f48ab7bd75b..2e9813ecfd7d 100644 > > --- a/arch/xtensa/kernel/syscalls/syscall.tbl > > +++ b/arch/xtensa/kernel/syscalls/syscall.tbl > > @@ -408,3 +408,4 @@ > > 435 common clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > > index 433c8c85636e..1b58a11ff49f 100644 > > --- a/include/linux/syscalls.h > > +++ b/include/linux/syscalls.h > > @@ -877,6 +877,8 @@ asmlinkage long sys_munlockall(void); > > asmlinkage long sys_mincore(unsigned long start, size_t len, > > unsigned char __user * vec); > > asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior); > > +asmlinkage long sys_process_madvise(int pidfd, unsigned long start, > > + size_t len, int behavior, unsigned long flags); > > asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size, > > unsigned long prot, unsigned long pgoff, > > unsigned long flags); > > diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h > > index 33f3856a9c3c..4bcd8d366f38 100644 > > --- a/include/uapi/asm-generic/unistd.h > > +++ b/include/uapi/asm-generic/unistd.h > > @@ -856,8 +856,11 @@ __SYSCALL(__NR_watch_devices, sys_watch_devices) > > #define __NR_openat2 437 > > __SYSCALL(__NR_openat2, sys_openat2) > > > > +#define __NR_openat2 438 > > Shouldn't this be '#define __NR_process_madvise 438'? > Hi SeongJae, I fixed all you pointed out. Thanks for the review.