Subject: Re: Semaphore limits!! - msg#00215

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lvcreate -- ERROR "Cannot allocate memory" creating VGDA

Hi All, I am trying the following "lvcreate" command and I am hit an error. I googled for this error, and I can see it being listed in lotz of places, but without any solution or workaround. Configuration: ---------------------- RH-Linux 2.4.26 1GB memory. But the same command works fine, if I have only 512 MB RAM. Any help is highly appreciated. Thanks Shesha --------------- [root@mc26300a root]# lvcreate -s -l 4306 -n stest /dev/VG_H41/LV_H41 lvcreate -- WARNING: the snapshot will be automatically disabled once it gets full lvcreate -- INFO: using default snapshot chunk size of 64 KB for "/dev/VG_H41/ste1" lvcreate -- ERROR "Cannot allocate memory" creating VGDA for "/dev/VG_H41/ste1" in kernel ---------------- -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/

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problem in initilisation

HI, I wrote one character device which should create network device. When I do insmod it gave a segmentation fault and lsmod shows initializing. A dmesg shows: EIP is at init_module [testdriver] 0xa6 (2.4.18-14) eax: 00000000 ebx: ffffffea ecx: c05b6000 edx: c8e7f4d3 esi: 00000000 edi: 00000000 ebp: c672df18 esp: c672df00 ds: 0018 es: 0018 ss: 0018 Process insmod (pid: 9922, stackpage=c672d000) Stack: 00200206 ffffffff 00002f3f c05b6940 00000000 00000000 c8e7f000 c011bf79 c8e7f060 08075228 00000908 00000000 080756f4 0000052c 00000060 00000060 0000000a c05b6c40 c6231000 c6e7e000 00000060 c8def000 c8e7f060 00000968 Call Trace: [<c011bf79>] sys_init_module [kernel] 0x4d9 (0xc672df1c)) [<c8e7f060>] test_open [testdriver] 0x0 (0xc672df20)) [<c8e7f060>] test_open [testdriver] 0x0 (0xc672df58)) [<c010910f>] system_call [kernel] 0x33 (0xc672dfc0)) Code: c7 40 34 fe f0 e7 c8 83 ec 08 68 d4 f4 e7 c8 8b 45 f4 ff 30 I am attaching the code, pls help me to solve this problem. Thanks a lot, -Ravi #ifndef __KERNEL__ # define __KERNEL__ #endif #ifndef MODULE # define MODULE #endif #define DEVNAME "testdev" #include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/slab.h> #include <linux/netdevice.h> #include <linux/if_ether.h> int test_open(struct inode *,struct file *); int test_release(struct inode *,struct file*); struct test_struct{ struct net_device *dev; char name[IFNAMSIZ]; }; struct file_operations test_fop={ llseek: NULL, read: NULL, write: NULL, ioctl: NULL, open: test_open, release: test_release, }; int test_open(struct inode *inode, struct file *filep) { MOD_INC_USE_COUNT; return 0; } int test_release(struct inode *inode, struct file *filep) { MOD_DEC_USE_COUNT; return 0; } int testdev_open(struct net_device *dev) { MOD_INC_USE_COUNT; return 0; } int testdev_close(struct net_device *dev) { unregister_netdev(dev); MOD_DEC_USE_COUNT; return 0; } static int test_init_dev(struct net_device *dev) { struct test_struct *c; dev->priv = kmalloc(sizeof(struct net_device),GFP_KERNEL); if(!dev->priv) { printk(KERN_ERR "out of memory while allocating to dev->priv\n"); return -ENOMEM; } c = (struct test_struct *)dev->priv; if(!c) return -ENODEV; memset(c,0,sizeof(struct test_struct)); c->dev = dev; ether_setup(dev); dev->open = testdev_open; dev->stop = testdev_close; dev->mtu = ETH_DATA_LEN; dev_init_buffers(dev); return 0; } int init_module(void) { int result,i; struct test_struct *pTestStruct; result = register_chrdev(16,"test",&test_fop); if( result < 0 ){ printk(KERN_WARNING "test: cant get major\n"); return result; } pTestStruct = (struct test_struct *)kmalloc(sizeof( struct test_struct),GFP_KERNEL); if(!pTestStruct) { printk(KERN_ERR "failed to allocate memory\n"); return -ENOMEM; } memset((void *)pTestStruct,0,sizeof(pTestStruct)); sprintf(pTestStruct->name, DEVNAME); //pTestStruct->dev->priv = pTestStruct; pTestStruct->dev->init = test_init_dev; i = dev_alloc_name(pTestStruct->dev,"testdev%d"); if(i < 0 ) { printk(KERN_ERR "cant allocate device\n"); return -ENODEV; } i = register_netdevice((pTestStruct->dev)); if( i < 0 ) printk(KERN_ERR "register netdevice failed\n"); return 0; } void cleanup_module(void) { unregister_chrdev(16,"test"); }

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Re: Semaphore limits!!

thanx Suman, surely its a great help. -praveen. ----- Original Message ----- From: "Suman Puthana" <suman@xxxxxxxxxxxxx> To: "Praveen Nair" <praveen.nair@xxxxxxxxx>; <kernelnewbies@xxxxxxxxxxxx> Sent: Sunday, April 18, 2004 6:43 PM Subject: Re: Semaphore limits!! > Praveen, > > Yes, you can. And you have answered the how part of it urself - By modifying > the /proc/sys/kernel/sem to the appropriate numbers. > > This is how I do it: > > "echo 32 65792 32 2056 > /proc/sys/kernel/sem" and it has been working > pretty well for me. > > Suman Puthana, > > Member of Technical Staff, > BroadWare Technologies. > > ----- Original Message ----- > From: "Praveen Nair" <praveen.nair@xxxxxxxxx> > To: <kernelnewbies@xxxxxxxxxxxx> > Sent: Friday, April 16, 2004 11:36 PM > Subject: Semaphore limits!! > > > > Hi, > > ipcs -l tells me that the limit for number of semaphore arrays is 128 > > where each array can grow upto 250 semaphores...now my question > > is, can i have more than 128 semaphore arrays if i can live with lesser > > number of semaphores per array, the limit for system wide semaphore > > not exceeding?? > > another doubt is can i modify the /proc/sys/kernel/sem file for the > same?? > > > > any help is valuable :) > > > > Thanks in advance.. > > > > -praveen. > > > > > > > > -- > > Kernelnewbies: Help each other learn about the Linux kernel. > > Archive: http://mail.nl.linux.org/kernelnewbies/ > > FAQ: http://kernelnewbies.org/faq/ > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/

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Re: Semaphore limits!!

thanx suresh, but another doubt that lingers in my mind is can i exceed the 32000 limits and keep within 32767?? since semaphore ids can range from 0 to 32767... -praveen. ----- Original Message ----- From: "Suresh Jayaram" <sureshj@xxxxxxxxxxxxxx> To: "kernelnewbies" <kernelnewbies@xxxxxxxxxxxx> Cc: "Praveen Nair" <praveen.nair@xxxxxxxxx> Sent: Monday, April 19, 2004 10:30 AM Subject: Re: Semaphore limits!! > > Suman Wrote: > > > > Yes, you can. And you have answered the how part of it urself - By > modifying > > > the /proc/sys/kernel/sem to the appropriate numbers. > > >> > This is how I do it: > > >> > "echo 32 65792 32 2056 > /proc/sys/kernel/sem" > > Quickly setting values like this in /proc/sys is helpful during testing. > However these special settings are lost when the machine is rebooted. > To preserve the settings and to make permanently to your kernel, add them to > the /etc/sysctl.conf file. > > $man sysctl > > JS > > "Software is like sex, better when it is free" > - Linus Torvalds > > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/