March 2015 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Question about ixgbe and ixgbevf
by Kevin Wilson March 23, 2015

March 23, 2015

Hi, I have an x86_64 machine (F21) on which ixgbevf is not loaded. I notices that when running modprobe ixgbevf max_vfs = 10 (or any other number), this triggers loading of ixgbevf driver. I will appreciate if someone can exaplain the implementation details of how does this happen. I could not find what in the ixgbe driver code triggers this action Regards, Kevni

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Question abount bh_lru_lock()
by Rock Lee March 23, 2015

March 23, 2015

Hi, all: Going through fs/buffer.c, I find that bh_lru_lock() is a macro which can be local_irq_disable() or preempt_disable(). #ifdef CONFIG_SMP #define bh_lru_lock() local_irq_disable() #define bh_lru_unlock() local_irq_enable() #else #define bh_lru_lock() preempt_disable() #define bh_lru_unlock() preempt_enable() #endif In SMP system, bh_lru_lock just disables local interrupt, if current kernel is preemptible, how can bh_lru_lock protect critical region? or In UP system, is making the kernel just non-preemptible safe enough when an interrupt occur and its handler may modify critical region?

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Re: Delivery Status Notification (Failure)
by s.rawat March 23, 2015

March 23, 2015

More over I also found that : scan_elements/in_*_x_en has value = -1 instead of 0 or 1 .Could this be the cause for this? Thanks and Rgds, Saurabh On Mon, Mar 23, 2015 at 10:58 AM, Mail Delivery Subsystem < mailer-daemon(a)googlemail.com> wrote: > Delivery to the following recipient failed permanently: > > linux-iio(a)vger.kernel.org > > Technical details of permanent failure: > Google tried to deliver your message, but it was rejected by the server > for the recipient domain vger.kernel.org by vger.kernel.org. > [209.132.180.67]. > > The error that the other server returned was: > 550 5.7.1 Content-Policy reject msg: The message contains HTML subpart, > therefore we consider it SPAM or Outlook Virus. TEXT/PLAIN is accepted.! > BF:<H 0.340883>; S1752369AbbCWF2O > > > ----- Original message ----- > > DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; > d=gmail.com; s=20120113; > h=mime-version:from:date:message-id:subject:to:content-type; > bh=W+21xGol3QXRz/AvvkDAa++sfkPFzpaeG7bCHFWwCK4=; > > b=W24U0Vx1L94eBofJD/jfz8XA3wklJQcDDewTbOXPXQBBOJBuZQv4Q2SQ2FCVzBtcx0 > > bbyECGWi5OwG3CZkW/bk7Z8lHbhbkiwNAzVZk9k3/RTxPWjIQT9kxVesJckBy6dq9lr2 > > C/if1bV0EYyKYAuB1QPp+k+srcrfRrfawkz87nGEFu147Ocnn/ilMcBVuQLegjVZRC0Y > > 4AVXRtzIurvk7zOekGldYbgHGiRy+iHitSwXAtbN6pTc1bpG1dniN29ErGIq6dBcqBNI > > A4RDC+9A85CEezW1rTdSz4BYvFOE5UhfeDwGfy4nRKwdw38MhBiyDmDTLb5x1KqNrK/x > 0H7w== > X-Received: by 10.55.22.213 with SMTP id > 82mr135607224qkw.103.1427088493423; > Sun, 22 Mar 2015 22:28:13 -0700 (PDT) > MIME-Version: 1.0 > Received: by 10.140.157.148 with HTTP; Sun, 22 Mar 2015 22:27:52 -0700 > (PDT) > From: "s.rawat" <imsaurabhrawat(a)gmail.com> > Date: Mon, 23 Mar 2015 10:57:52 +0530 > Message-ID: <CALwa49u4s7qqBUbV8FUU= > 3dFJczEkzQwXZAEhakxGY1Xay-8iA(a)mail.gmail.com> > Subject: Sysfs requirement for running generic_buffer.c application - IIO > sensors > To: kernelnewbies <kernelnewbies(a)kernelnewbies.org>, > "linux-iio(a)vger.kernel.org" <linux-iio(a)vger.kernel.org> > Content-Type: multipart/alternative; boundary=001a114904d6b6b16e0511edee04 > > I have two system having different kernel version and drivers(IIO) on which > i can run the generic_buffer.c application .On one system it works fine but > on the other it does not give the input reports data. > > I have checked that the system on which it is working has the following > sysfs under /sys/bus/iio/devices/iio:deviceX (where X is 1,2,3...) > > buffer > dev > in_accel_hysteresis > in_accel_offset > in_accel_sampling_frequency > in_accel_scale > *in_accel_x_raw* > > *in_accel_y_raw* > *in_accel_z_raw* > name > power > scan_elements > subsystem > trigger > uevent > > This is for accelerometer similiarly for magnetometer > (in_magn_x_raw,_y_raw,z_raw etc) and for Gyrometer ( > in_anglvel_x_raw,in_anglvel_y_raw,in_anglvel_z_raw ) > > > > and the one on which it is not working has the below sysfs under > /sys/bus/iio/devices/iio:deviceX (where X is 1,2,3...) : > > buffer > dev > in_accel_hysteresis > in_accel_offset > in_accel_sampling_frequency > in_accel_scale > name > power > scan_elements > subsystem > trigger > uevent > > > > Is the missing _x_raw,_y_raw and _z_raw component main reason for not > working of the app,.Where I can enable them in the driver? > > > > Thanks and Rgds, > Saurabh >

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Scull Driver - Read
by sahil aggarwal March 21, 2015

March 21, 2015

hi all, Going through scull driver code, i see read function reads only till end of 1 quantum, so do kernel call read multiple times if count from q_pos exceeds quantum size limit.? Ref: ldd3. if(count > quantum - q_pos) count = quantum - q_pos; if(copy_to_user(buf, dptr->data[s_pos] + q_pos,count)){ retval = -EFAULT; goto out; } *f_pos += count; retval = count; Thanks Regards

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Re: Raw binary Image of linux
by victorascroft＠gmail.com March 18, 2015

March 18, 2015

Hello, On 15-03-17 11:42:01, chirag garg wrote: > Hello sir, You do not have to call me or anyone sir. We are probably of the same age. :p > > I changed my uboot version to 2014.07 and tried the following commands on > the board. > > u-bbot> mmc dev 1 > u-boot>fatload mmc 1:1 0x11000000 imx6q-sabresd.dtb > u-boot>fatload mmc 1:1 0x12000000 uImage > u-boot>bootm 0x12000000 - 0x11000000 > > I got the following output: > > ## Booting kernel from Legacy Image at 12000000 ... > Image Name: Linux-3.18.4 > Image Type: ARM Linux Kernel Image (uncompressed) > Data Size: 5445640 Bytes = 5.2 MiB > Load Address: 10001000 > Entry Point: 10001000 > Verifying Checksum ... OK > ## Flattened Device Tree blob at 11000000 > Booting using the fdt blob at 0x11000000 > Loading Kernel Image ... OK > Loading Device Tree to 4f33f000, end 4f34a5ac ... OK > > Starting kernel ... > > So what could be the reason behind this ? And as you said in previous mail > to check environment variable ? which variable should i check to debug this > ? Try loading the uImage to 0x10800000 and the dtb blob at 0x12000000. Perhaps that will work. So now it becomes bootm 0x10800000 - 0x12000000? If it doesn't so now this needs to be debug. Enable CONFIG_DEBUG_LL and CONFIG_EARLY_PRINTK options and see if you get some more debug messages. When I said check environment variables, I meant if there any any variables which the uboot for sabre might have predefined. It would be helpful to have a look. - Sanchayan. > > Regards > > Chirag Garg > IIT Madras , Rise Lab > > On Mon, Mar 16, 2015 at 11:09 AM, <victorascroft(a)gmail.com> wrote: > > > Hello, > > > > On 15-03-16 09:59:33, chirag garg wrote: > > > Hi, > > > > > > On Mon, Mar 16, 2015 at 9:45 AM, <victorascroft(a)gmail.com> wrote: > > > > > > > Hello, > > > > > > > > On 15-03-16 09:33:21, chirag garg wrote: > > > > > Hello , > > > > > > > > > > I perform the following steps to run linux kernel on imx6: > > > > > > > > > > Download 3.18 kernel from www.kernel.org > > > > > Make steps: > > > > > make CROSSarm-linux-gnueabi- ARCH=arm imx_v6_v7_defconfig > > > > > make CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm uImage > > LOADADDR=10001000 > > > > > > > > > > cp linux-3.18.4/arch/arm/boot/uImage Sd_card > > > > > > > > So you copied the kernel image to SD card. > > > > > > > > > Run uImage on the imx6 board... > > > > > > > > Can you provide some more information on this point? When you copied > > the > > > > uImage to SD card, did you do something else to perhaps update the > > > > uImage on the module, or is the module setup to boot from SD card? And > > > > what about the device tree blob? Did you have a look at the uboot > > > > environment variables? > > > > > > > > I perform the following steps on imx6 board: > > > mmc dev 1 > > > fatload mmc 1:1 0x10800000 uImage > > > bootm 10800000 > > > > > > I havn't use device tree blob to run this image. > > > > Device tree will be absolutely required. You will probably need to set > > the uboot environment variables correctly. Newer kernels use the > > information from device tree to set things up. > > > > You probably need something like this > > > > u-boot>tftpboot 0x11000000 imx6q-sabresd.dtb > > u-boot>tftpboot 0x12000000 uImage > > u-boot>bootm 0x12000000 - 0x11000000 > > > > Have a look here. Also what is your uboot version? Perhaps you will have > > to upgrade your uboot as well. > > https://community.freescale.com/thread/313457 > > > > > > > > > > > > What was the earlier kernel version the board was booting with? > > > > > > > > > Earlier, I used the following linux kernel: > > > > > http://boundarydevices.com/cross-compile-i-mx6-kernel-using-ltib-toolchain/ > > > > > > which was successfully booting. > > > Kernel version is 3.0.35. > > > > > > > Ancient kernel that used board files and not device trees. > > > > - Sanchayan. > > > > > > > > > > > > > > > Output : > > > > > > > > > > ## Booting kernel from Legacy Image at 10800000 ... > > > > > Image Name: Linux-3.18.4 > > > > > Image Type: ARM Linux Kernel Image (uncompressed) > > > > > Data Size: 5445640 Bytes = 5.2 MB > > > > > Load Address: 10001000 > > > > > Entry Point: 10001000 > > > > > Verifying Checksum ... OK > > > > > Loading Kernel Image ... OK > > > > > OK > > > > > > > > > > Starting kernel ... > > > > > > > > > > > > > > > what could be the problem in this ? why Is this kernel not able > > start on > > > > > imx6 platform ? > > > > > > > > That output is on the serial debug console? Is the console parameter in > > > > uboot set appropriately to what the kernel expects? > > > > > > > > - Sanchayan. > > > > > > > > > > > > > > Thanks in advance, > > > > > Regards, > > > > > > > > > > Chirag Garg > > > > > IIT Madras , Rise Lab > > > > > > > > > > On Mon, Mar 9, 2015 at 11:01 PM, <victorascroft(a)gmail.com> wrote: > > > > > > > > > > > Hello, > > > > > > > > > > > > On 15-03-09 21:53:34, chirag garg wrote: > > > > > > > Hello, > > > > > > > > > > > > > > On Mon, Mar 9, 2015 at 9:01 PM, <victorascroft(a)gmail.com> wrote: > > > > > > > > > > > > > > > Hello, > > > > > > > > > > > > > > > > On 15-03-09 11:20:55, chirag garg wrote: > > > > > > > > > Hi all, > > > > > > > > > > > > > > > > > > I am new to the linux kernel source code. I want to compile > > linux > > > > > > source > > > > > > > > > code for imx6 ARM based platform. > > > > > > > > > I want to generate raw binary image (.bin file) and .dtb > > file. > > > > Can > > > > > > any > > > > > > > > one > > > > > > > > > help me in this.? > > > > > > > > > > > > > > > > Which iMX6 platform is this? Depending on the platform, it > > would > > > > be as > > > > > > > > simple as doing make imx_v6_v7_defconfig and then using the > > > > correct dtb > > > > > > > > for the platform. Boards like Nitrogen, Sabre or Wandaboard > > should > > > > boot > > > > > > > > easily with the recent kernels. > > > > > > > > > > > > > > > > I am using freescale imx6 quad core saberlite board. Available > > on > > > > the > > > > > > > freescale site > > > > > > > > > > > http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=i.MX6Q > > > > > > > > > > > > > > Where should be this dtb available according to the board. I am > > > > trying to > > > > > > > boot 3.14 linux kernel. > > > > > > > > > > > > The DTS files for all ARM boards are available in the following > > > > > > directory > > > > > > > > > > > > http://lxr.free-electrons.com/source/arch/arm/boot/dts/?v=3.14 > > > > > > > > > > > > > > > > > > > > > > > > http://lxr.free-electrons.com/source/arch/arm/configs/imx_v6_v7_defconfig?v… > > > > > > > > > > > > imx_v6_v7_defconfig is the config file for imx platform. > > > > > > > > > > > > -Regards, > > > > > > Sanchayan. > > > > > > > > > > > > > > > > > > > > > > > > > > > > Do you have a custom board or one of those easily available > > > > development > > > > > > > > platforms? > > > > > > > > > > > > > > > > Board is easily available in the market. > > > > > > > > > > > > > > > > > > > > > > - Regards, > > > > > > > > Sanchayan.. > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks in advance > > > > > > > > > Regards > > > > > > > > > > > > > > > > > > Chirag Garg > > > > > > > > > IIT Madras , Rise Lab > > > > > > > > > > > > > > > > > > > > > > > Regards > > > > > > > Chirag Garg > > > > > > > IIT Madras , Rise Lab > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > > Kernelnewbies mailing list > > > > > > > > > Kernelnewbies(a)kernelnewbies.org > > > > > > > > > > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > > > > > > > > > > > > > > > > > > > > > > > > > >

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use of dev->dev_t
by Malte Vesper March 17, 2015

March 17, 2015

Hi, I am trying to write a driver that uses the MINOR(dev_t) to identify cards. Since it is a PCI driver and I get pcidev->dev.dev_t anyway. I thought about not bothering to store the minor number of the device. However if I look at pcidev->dev.dev_t in the remove function (the driver frameworks remove), I always get pcidev->dev.dev_t == 0. Is this the intended behaviour and if so why? (This means I have to store the minor separatly to call device_destroy()) Thanks Malte FYI: I am running a 3.19.0 Kernel

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Android Binder Issue
by David Legault March 17, 2015

March 17, 2015

Hello, I'm trying to debug an issue I'm encountering on kernel 3.4 in the android binder. Basically in the function binder_update_page_range it allocates a page. If I understand correctly the next part, it maps this page_addr to the page in kernel space and then maps the user process addr to the same page. http://lxr.free-electrons.com/source/drivers/staging/android/binder.c?v=3.4… If I attempt to use virt_to_head_page(page_addr) after all this is accomplished, I should get back the page that was just allocated and mapped, but that's not what I observe on my system as seen in the log below. [ 20.960786] ( 25.557586) binder_open: 219:219 [ 20.960827] ( 25.557617) binder_ioctl: 219:219 c0046209 be9a7938 [ 20.960841] ( 25.557617) binder_ioctl: 219:219 40046205 be9a793c [ 20.960857] ( 25.557647) binder_mmap: 219 b6c02000-b6d00000 (1016 K) vma 200071 pagep 79f [ 20.960907] ( 25.557708) binder: 219: allocate pages cb300000-cb301000 *** binder allocated page here (nil == first_page value) [ 20.960922] ( 25.557708) binder: page_alloc cd958238 (nil) *** dump of the page [ 20.960931] ( 25.557708) page:cd958238 count:1 mapcount:0 mapping: (nil) index:0x0 [ 20.960939] ( 25.557739) page flags: 0x0() *** first attempt of virt_to_head_page(page_addr) before kernel mapping + dump of returned page *** which shows it's uninitialized (aaaaaaaa = first_page value) [ 20.960947] ( 25.557739) virt_to_head_page cd392c00 [ 20.960955] ( 25.557739) compound_head_by_tail cd392c00 aaaaaaaa [ 20.960965] ( 25.557769) page:cd392c00 count:-1431655766 mapcount:-1431655765 mapping:aaaaaaaa index:0xaaaaaaaa [ 20.960973] ( 25.557769) page flags: 0xaaaaaaaa(error|uptodate|lru|slab|arch_1|private|writeback|tail|mappedtodisk|swapbacked|mlocked) [ 20.960981] ( 25.557769) virt_to_head_page cd9681bc [ 20.960997] ( 25.557800) virt_to_head_page cd967c1c *** before kernel + user space mapping calls [ 20.961551] ( 25.558349) binder: addr cb300000 page aaaaaaaa *** after kernel + user space mapping calls - dump allocated page again [ 20.961566] ( 25.558349) page:cd958238 count:2 mapcount:1 mapping: (nil) index:0x0 [ 20.961574] ( 25.558380) page flags: 0x200(arch_1) *** second attempt of virt_to_head_page(page_addr) expecting *** that allocated page above would be mapped to this address [ 20.961584] ( 25.558380) binder: addr cb300000 page aaaaaaaa [ 20.961595] ( 25.558380) binder: 219: add free buffer, size 1040344, at cb300000 [ 20.961605] ( 25.558410) binder_mmap: 219 b6c02000-b6d00000 maps cb300000 … Blows up on invalid page access 'aaaaaaaa' a while later. Thanks David

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Kernel booting stuck at "CPU1: Booted secondary processor"
by AYAN KUMAR HALDER March 17, 2015

March 17, 2015

Hi, I am porting kernel (3.14.22) on a custom ARM(Cortex A9 x 3) based platform. I was able to get it working on uniprocessor mode. Now I wish to get the SMP mode working as mine is Cortex A9 x3 platform. However, I see that the booting gets stuck after the following log:- CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 Setting up static identity map for 0x1f9690 - 0x1f96c4 CPU1: Booted secondary processor When I debugged it further, I found that it waits endlessly in a arch_spin_lock() :- while (lockval.tickets.next != lockval.tickets.owner) { // loops here wfe(); lockval.tickets.owner = ACCESS_ONCE(lock->tickets.owner); } It would be great if someone can give me pointers about how to proceed ahead. Regards, Ayan kumar Halder

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Re: Raw binary Image of linux
by victorascroft＠gmail.com March 17, 2015

March 17, 2015

Hello, On 15-03-16 09:59:33, chirag garg wrote: > Hi, > > On Mon, Mar 16, 2015 at 9:45 AM, <victorascroft(a)gmail.com> wrote: > > > Hello, > > > > On 15-03-16 09:33:21, chirag garg wrote: > > > Hello , > > > > > > I perform the following steps to run linux kernel on imx6: > > > > > > Download 3.18 kernel from www.kernel.org > > > Make steps: > > > make CROSSarm-linux-gnueabi- ARCH=arm imx_v6_v7_defconfig > > > make CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm uImage LOADADDR=10001000 > > > > > > cp linux-3.18.4/arch/arm/boot/uImage Sd_card > > > > So you copied the kernel image to SD card. > > > > > Run uImage on the imx6 board... > > > > Can you provide some more information on this point? When you copied the > > uImage to SD card, did you do something else to perhaps update the > > uImage on the module, or is the module setup to boot from SD card? And > > what about the device tree blob? Did you have a look at the uboot > > environment variables? > > > > I perform the following steps on imx6 board: > mmc dev 1 > fatload mmc 1:1 0x10800000 uImage > bootm 10800000 > > I havn't use device tree blob to run this image. Device tree will be absolutely required. You will probably need to set the uboot environment variables correctly. Newer kernels use the information from device tree to set things up. You probably need something like this u-boot>tftpboot 0x11000000 imx6q-sabresd.dtb u-boot>tftpboot 0x12000000 uImage u-boot>bootm 0x12000000 - 0x11000000 Have a look here. Also what is your uboot version? Perhaps you will have to upgrade your uboot as well. https://community.freescale.com/thread/313457 > > > > What was the earlier kernel version the board was booting with? > > > Earlier, I used the following linux kernel: > http://boundarydevices.com/cross-compile-i-mx6-kernel-using-ltib-toolchain/ > > which was successfully booting. > Kernel version is 3.0.35. > Ancient kernel that used board files and not device trees. - Sanchayan. > > > > > > > Output : > > > > > > ## Booting kernel from Legacy Image at 10800000 ... > > > Image Name: Linux-3.18.4 > > > Image Type: ARM Linux Kernel Image (uncompressed) > > > Data Size: 5445640 Bytes = 5.2 MB > > > Load Address: 10001000 > > > Entry Point: 10001000 > > > Verifying Checksum ... OK > > > Loading Kernel Image ... OK > > > OK > > > > > > Starting kernel ... > > > > > > > > > what could be the problem in this ? why Is this kernel not able start on > > > imx6 platform ? > > > > That output is on the serial debug console? Is the console parameter in > > uboot set appropriately to what the kernel expects? > > > > - Sanchayan. > > > > > > > > Thanks in advance, > > > Regards, > > > > > > Chirag Garg > > > IIT Madras , Rise Lab > > > > > > On Mon, Mar 9, 2015 at 11:01 PM, <victorascroft(a)gmail.com> wrote: > > > > > > > Hello, > > > > > > > > On 15-03-09 21:53:34, chirag garg wrote: > > > > > Hello, > > > > > > > > > > On Mon, Mar 9, 2015 at 9:01 PM, <victorascroft(a)gmail.com> wrote: > > > > > > > > > > > Hello, > > > > > > > > > > > > On 15-03-09 11:20:55, chirag garg wrote: > > > > > > > Hi all, > > > > > > > > > > > > > > I am new to the linux kernel source code. I want to compile linux > > > > source > > > > > > > code for imx6 ARM based platform. > > > > > > > I want to generate raw binary image (.bin file) and .dtb file. > > Can > > > > any > > > > > > one > > > > > > > help me in this.? > > > > > > > > > > > > Which iMX6 platform is this? Depending on the platform, it would > > be as > > > > > > simple as doing make imx_v6_v7_defconfig and then using the > > correct dtb > > > > > > for the platform. Boards like Nitrogen, Sabre or Wandaboard should > > boot > > > > > > easily with the recent kernels. > > > > > > > > > > > > I am using freescale imx6 quad core saberlite board. Available on > > the > > > > > freescale site > > > > > > > http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=i.MX6Q > > > > > > > > > > Where should be this dtb available according to the board. I am > > trying to > > > > > boot 3.14 linux kernel. > > > > > > > > The DTS files for all ARM boards are available in the following > > > > directory > > > > > > > > http://lxr.free-electrons.com/source/arch/arm/boot/dts/?v=3.14 > > > > > > > > > > > > > > http://lxr.free-electrons.com/source/arch/arm/configs/imx_v6_v7_defconfig?v… > > > > > > > > imx_v6_v7_defconfig is the config file for imx platform. > > > > > > > > -Regards, > > > > Sanchayan. > > > > > > > > > > > > > > > > > > > > Do you have a custom board or one of those easily available > > development > > > > > > platforms? > > > > > > > > > > > > Board is easily available in the market. > > > > > > > > > > > > > > > > - Regards, > > > > > > Sanchayan.. > > > > > > > > > > > > > > > > > > > > Thanks in advance > > > > > > > Regards > > > > > > > > > > > > > > Chirag Garg > > > > > > > IIT Madras , Rise Lab > > > > > > > > > > > > > > > > > Regards > > > > > Chirag Garg > > > > > IIT Madras , Rise Lab > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > Kernelnewbies mailing list > > > > > > > Kernelnewbies(a)kernelnewbies.org > > > > > > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > > > > > > > > > > > > > > > >

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Is RCU not safe enough to protect dcache hlist?
by Lee March 16, 2015

March 16, 2015

Hi, all: I am studying the dcache in VFS recently . I found that hlist of dcache is already protected by RCU in __d_lookup.Is it necessary for the function -- d_lookup using sequence lock to protect the hlist again? struct dentry * d_lookup(struct dentry * parent, struct qstr * name) { struct dentry * dentry = NULL; unsigned long seq; do { seq = read_seqbegin(&rename_lock); dentry = __d_lookup(parent, name); if (dentry) break; } while (read_seqretry(&rename_lock, seq)); return dentry; } Thanks --- Rock Lee

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