From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: Re: [PATCH v2] locks: Filter /proc/locks output on proc pid ns Date: Wed, 03 Aug 2016 09:46:52 -0400 Message-ID: <1470232012.18285.4.camel@poochiereds.net> References: <1470148943-21835-1-git-send-email-kernel@kyup.com> <1470209710-30022-1-git-send-email-kernel@kyup.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <1470209710-30022-1-git-send-email-kernel-6AxghH7DbtA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Nikolay Borisov , bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: containers.vger.kernel.org T24gV2VkLCAyMDE2LTA4LTAzIGF0IDEwOjM1ICswMzAwLCBOaWtvbGF5IEJvcmlzb3Ygd3JvdGU6 Cj4gT24gYnVzeSBjb250YWluZXIgc2VydmVycyByZWFkaW5nIC9wcm9jL2xvY2tzIHNob3dzIGFs bCB0aGUgbG9ja3MKPiBjcmVhdGVkIGJ5IGFsbCBjbGllbnRzLiBUaGlzIGNhbiBjYXVzZSBsYXJn ZSBsYXRlbmN5IHNwaWtlcy4gSW4gbXkKPiBjYXNlIEkgb2JzZXJ2ZWQgbHNvZiB0YWtpbmcgdXAg dG8gNS0xMCBzZWNvbmRzIHdoaWxlIHByb2Nlc3NpbmcgYXJvdW5kCj4gNTBrIGxvY2tzLiBGaXgg dGhpcyBieSBsaW1pdGluZyB0aGUgbG9ja3Mgc2hvd24gb25seSB0byB0aG9zZSBjcmVhdGVkCj4g aW4gdGhlIHNhbWUgcGlkbnMgYXMgdGhlIG9uZSB0aGUgcHJvYyB3YXMgbW91bnRlZCBpbi4gV2hl biByZWFkaW5nCj4gL3Byb2MvbG9ja3MgZnJvbSB0aGUgaW5pdF9waWRfbnMgc2hvdyBldmVyeXRo aW5nLgo+IAo+ID4gU2lnbmVkLW9mZi1ieTogTmlrb2xheSBCb3Jpc292IDxrZXJuZWxAa3l1cC5j b20+Cj4gLS0tCj4gwqBmcy9sb2Nrcy5jIHwgNiArKysrKysKPiDCoDEgZmlsZSBjaGFuZ2VkLCA2 IGluc2VydGlvbnMoKykKPiAKPiBkaWZmIC0tZ2l0IGEvZnMvbG9ja3MuYyBiL2ZzL2xvY2tzLmMK PiBpbmRleCBlZTFiMTVmNmZjMTMuLjc1MTY3M2Q3ZjdmYyAxMDA2NDQKPiAtLS0gYS9mcy9sb2Nr cy5jCj4gKysrIGIvZnMvbG9ja3MuYwo+IEBAIC0yNjQ4LDkgKzI2NDgsMTUgQEAgc3RhdGljIGlu dCBsb2Nrc19zaG93KHN0cnVjdCBzZXFfZmlsZSAqZiwgdm9pZCAqdikKPiDCoHsKPiA+IMKgCXN0 cnVjdCBsb2Nrc19pdGVyYXRvciAqaXRlciA9IGYtPnByaXZhdGU7Cj4gPiDCoAlzdHJ1Y3QgZmls ZV9sb2NrICpmbCwgKmJmbDsKPiA+ICsJc3RydWN0IHBpZF9uYW1lc3BhY2UgKnByb2NfcGlkbnMg PSBmaWxlX2lub2RlKGYtPmZpbGUpLT5pX3NiLT5zX2ZzX2luZm87Cj4gPiArCXN0cnVjdCBwaWRf bmFtZXNwYWNlICpjdXJyZW50X3BpZG5zID0gdGFza19hY3RpdmVfcGlkX25zKGN1cnJlbnQpOwo+ IMKgCj4gPiDCoAlmbCA9IGhsaXN0X2VudHJ5KHYsIHN0cnVjdCBmaWxlX2xvY2ssIGZsX2xpbmsp Owo+IMKgCj4gPiA+ICsJaWYgKChjdXJyZW50X3BpZG5zICE9ICZpbml0X3BpZF9ucykgJiYgZmwt PmZsX25zcGlkCgpPaywgc28gd2hlbiB5b3UgcmVhZCBmcm9tIGEgcHJvY2VzcyB0aGF0J3MgaW4g dGhlIGluaXRfcGlkX25zCm5hbWVzcGFjZSwgdGhlbiB5b3UnbGwgZ2V0IHRoZSB3aG9sZSBwaWxl IG9mIGxvY2tzLCBldmVuIHdoZW4gcmVhZGluZwp0aGlzIGZyb20gYSBmaWxlc3lzdGVtIHRoYXQg d2FzIG1vdW50ZWQgaW4gYSBkaWZmZXJlbnQgcGlkX25zPwoKVGhhdCBzZWVtcyBvZGQgdG8gbWUg aWYgc28uIEFueSByZWFzb24gbm90IHRvIGp1c3QgdW5pZm9ybWx5IHVzZSB0aGUKcHJvY19waWRu cyBoZXJlPwoKPiA+ID4gKwnCoMKgwqDCoCYmIChwcm9jX3BpZG5zICE9IG5zX29mX3BpZChmbC0+ ZmxfbnNwaWQpKSkKPiA+ICsJCXJldHVybiAwOwo+ICsKPiA+IMKgCWxvY2tfZ2V0X3N0YXR1cyhm LCBmbCwgaXRlci0+bGlfcG9zLCAiIik7Cj4gwqAKPiA+IMKgCWxpc3RfZm9yX2VhY2hfZW50cnko YmZsLCAmZmwtPmZsX2Jsb2NrLCBmbF9ibG9jaykKCi0tIApKZWZmIExheXRvbiA8amxheXRvbkBw b29jaGllcmVkcy5uZXQ+Cl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fCkNvbnRhaW5lcnMgbWFpbGluZyBsaXN0CkNvbnRhaW5lcnNAbGlzdHMubGludXgtZm91 bmRhdGlvbi5vcmcKaHR0cHM6Ly9saXN0cy5saW51eGZvdW5kYXRpb24ub3JnL21haWxtYW4vbGlz dGluZm8vY29udGFpbmVycw== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1470232012.18285.4.camel@poochiereds.net> Subject: Re: [PATCH v2] locks: Filter /proc/locks output on proc pid ns From: Jeff Layton To: Nikolay Borisov , bfields@fieldses.org Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, ebiederm@xmission.com, containers@lists.linux-foundation.org Date: Wed, 03 Aug 2016 09:46:52 -0400 In-Reply-To: <1470209710-30022-1-git-send-email-kernel@kyup.com> References: <1470148943-21835-1-git-send-email-kernel@kyup.com> <1470209710-30022-1-git-send-email-kernel@kyup.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On Wed, 2016-08-03 at 10:35 +0300, Nikolay Borisov wrote: > On busy container servers reading /proc/locks shows all the locks > created by all clients. This can cause large latency spikes. In my > case I observed lsof taking up to 5-10 seconds while processing around > 50k locks. Fix this by limiting the locks shown only to those created > in the same pidns as the one the proc was mounted in. When reading > /proc/locks from the init_pid_ns show everything. > > > Signed-off-by: Nikolay Borisov > --- >  fs/locks.c | 6 ++++++ >  1 file changed, 6 insertions(+) > > diff --git a/fs/locks.c b/fs/locks.c > index ee1b15f6fc13..751673d7f7fc 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -2648,9 +2648,15 @@ static int locks_show(struct seq_file *f, void *v) >  { > >   struct locks_iterator *iter = f->private; > >   struct file_lock *fl, *bfl; > > + struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; > > + struct pid_namespace *current_pidns = task_active_pid_ns(current); >   > >   fl = hlist_entry(v, struct file_lock, fl_link); >   > > > + if ((current_pidns != &init_pid_ns) && fl->fl_nspid Ok, so when you read from a process that's in the init_pid_ns namespace, then you'll get the whole pile of locks, even when reading this from a filesystem that was mounted in a different pid_ns? That seems odd to me if so. Any reason not to just uniformly use the proc_pidns here? > > > +     && (proc_pidns != ns_of_pid(fl->fl_nspid))) > > + return 0; > + > >   lock_get_status(f, fl, iter->li_pos, ""); >   > >   list_for_each_entry(bfl, &fl->fl_block, fl_block) -- Jeff Layton