From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752782AbaF0HiG (ORCPT ); Fri, 27 Jun 2014 03:38:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35585 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750756AbaF0HiE (ORCPT ); Fri, 27 Jun 2014 03:38:04 -0400 Message-ID: <53AD1F46.2080005@redhat.com> Date: Fri, 27 Jun 2014 09:37:42 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Steven Rostedt CC: linux-kernel@vger.kernel.org, Linus Torvalds , Ingo Molnar , Andrew Morton , Jiri Kosina , Michal Hocko , Jan Kara , Frederic Weisbecker , Dave Anderson , Petr Mladek , "Paul E. McKenney" , Konstantin Khlebnikov , "James E.J. Bottomley" , Gleb Natapov Subject: Re: [RFC][PATCH 1/5 v2] tracing: Add trace_seq_buffer_ptr() helper function References: <20140626214901.596791200@goodmis.org> <20140626220129.452783019@goodmis.org> <20140626210603.3f797c0c@gandalf.local.home> In-Reply-To: <20140626210603.3f797c0c@gandalf.local.home> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 27/06/2014 03:06, Steven Rostedt ha scritto: > > As this patch is in my 3.17 queue and it touches the kvm and scsi > tracepoint code, I figured I should at least do the courtesy of > notifying the maintainers of those subsystems. > > Do you have any issues with this going through my tree? If not, please > give me an Acked-by. No problem absolutely. Acked-by: Paolo Bonzini Paolo > Thanks! > > -- Steve > > On Thu, 26 Jun 2014 17:49:02 -0400 > Steven Rostedt wrote: > >> From: "Steven Rostedt (Red Hat)" >> >> There's several locations in the kernel that open code the calculation >> of the next location in the trace_seq buffer. This is usually done with >> >> p->buffer + p->len >> >> Instead of having this open coded, supply a helper function in the >> header to do it for them. This function is called trace_seq_buffer_ptr(). >> >> Signed-off-by: Steven Rostedt >> --- >> arch/x86/kvm/mmutrace.h | 2 +- >> drivers/scsi/scsi_trace.c | 16 ++++++++-------- >> include/linux/trace_seq.h | 15 +++++++++++++++ >> kernel/trace/trace_output.c | 14 +++++++------- >> 4 files changed, 31 insertions(+), 16 deletions(-) >> >> diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h >> index 9d2e0ffcb190..2e5652b62fd6 100644 >> --- a/arch/x86/kvm/mmutrace.h >> +++ b/arch/x86/kvm/mmutrace.h >> @@ -22,7 +22,7 @@ >> __entry->unsync = sp->unsync; >> >> #define KVM_MMU_PAGE_PRINTK() ({ \ >> - const char *ret = p->buffer + p->len; \ >> + const char *ret = trace_seq_buffer_ptr(p); \ >> static const char *access_str[] = { \ >> "---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux" \ >> }; \ >> diff --git a/drivers/scsi/scsi_trace.c b/drivers/scsi/scsi_trace.c >> index 2bea4f0b684a..503594e5f76d 100644 >> --- a/drivers/scsi/scsi_trace.c >> +++ b/drivers/scsi/scsi_trace.c >> @@ -28,7 +28,7 @@ scsi_trace_misc(struct trace_seq *, unsigned char *, int); >> static const char * >> scsi_trace_rw6(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> sector_t lba = 0, txlen = 0; >> >> lba |= ((cdb[1] & 0x1F) << 16); >> @@ -46,7 +46,7 @@ scsi_trace_rw6(struct trace_seq *p, unsigned char *cdb, int len) >> static const char * >> scsi_trace_rw10(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> sector_t lba = 0, txlen = 0; >> >> lba |= (cdb[2] << 24); >> @@ -71,7 +71,7 @@ scsi_trace_rw10(struct trace_seq *p, unsigned char *cdb, int len) >> static const char * >> scsi_trace_rw12(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> sector_t lba = 0, txlen = 0; >> >> lba |= (cdb[2] << 24); >> @@ -94,7 +94,7 @@ scsi_trace_rw12(struct trace_seq *p, unsigned char *cdb, int len) >> static const char * >> scsi_trace_rw16(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> sector_t lba = 0, txlen = 0; >> >> lba |= ((u64)cdb[2] << 56); >> @@ -125,7 +125,7 @@ scsi_trace_rw16(struct trace_seq *p, unsigned char *cdb, int len) >> static const char * >> scsi_trace_rw32(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len, *cmd; >> + const char *ret = trace_seq_buffer_ptr(p), *cmd; >> sector_t lba = 0, txlen = 0; >> u32 ei_lbrt = 0; >> >> @@ -180,7 +180,7 @@ out: >> static const char * >> scsi_trace_unmap(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> unsigned int regions = cdb[7] << 8 | cdb[8]; >> >> trace_seq_printf(p, "regions=%u", (regions - 8) / 16); >> @@ -192,7 +192,7 @@ scsi_trace_unmap(struct trace_seq *p, unsigned char *cdb, int len) >> static const char * >> scsi_trace_service_action_in(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len, *cmd; >> + const char *ret = trace_seq_buffer_ptr(p), *cmd; >> sector_t lba = 0; >> u32 alloc_len = 0; >> >> @@ -247,7 +247,7 @@ scsi_trace_varlen(struct trace_seq *p, unsigned char *cdb, int len) >> static const char * >> scsi_trace_misc(struct trace_seq *p, unsigned char *cdb, int len) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> >> trace_seq_printf(p, "-"); >> trace_seq_putc(p, 0); >> diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h >> index dd85753e1bb0..ea6c9dea79e3 100644 >> --- a/include/linux/trace_seq.h >> +++ b/include/linux/trace_seq.h >> @@ -25,6 +25,21 @@ trace_seq_init(struct trace_seq *s) >> s->full = 0; >> } >> >> +/** >> + * trace_seq_buffer_ptr - return pointer to next location in buffer >> + * @s: trace sequence descriptor >> + * >> + * Returns the pointer to the buffer where the next write to >> + * the buffer will happen. This is useful to save the location >> + * that is about to be written to and then return the result >> + * of that write. >> + */ >> +static inline unsigned char * >> +trace_seq_buffer_ptr(struct trace_seq *s) >> +{ >> + return s->buffer + s->len; >> +} >> + >> /* >> * Currently only defined when tracing is enabled. >> */ >> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c >> index b8930f79a04b..c6977d5a9b12 100644 >> --- a/kernel/trace/trace_output.c >> +++ b/kernel/trace/trace_output.c >> @@ -75,7 +75,7 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim, >> { >> unsigned long mask; >> const char *str; >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> int i, first = 1; >> >> for (i = 0; flag_array[i].name && flags; i++) { >> @@ -111,7 +111,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val, >> const struct trace_print_flags *symbol_array) >> { >> int i; >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> >> for (i = 0; symbol_array[i].name; i++) { >> >> @@ -122,7 +122,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val, >> break; >> } >> >> - if (ret == (const char *)(p->buffer + p->len)) >> + if (ret == (const char *)(trace_seq_buffer_ptr(p))) >> trace_seq_printf(p, "0x%lx", val); >> >> trace_seq_putc(p, 0); >> @@ -137,7 +137,7 @@ ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val, >> const struct trace_print_flags_u64 *symbol_array) >> { >> int i; >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> >> for (i = 0; symbol_array[i].name; i++) { >> >> @@ -148,7 +148,7 @@ ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val, >> break; >> } >> >> - if (ret == (const char *)(p->buffer + p->len)) >> + if (ret == (const char *)(trace_seq_buffer_ptr(p))) >> trace_seq_printf(p, "0x%llx", val); >> >> trace_seq_putc(p, 0); >> @@ -162,7 +162,7 @@ const char * >> ftrace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr, >> unsigned int bitmask_size) >> { >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> >> trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8); >> trace_seq_putc(p, 0); >> @@ -175,7 +175,7 @@ const char * >> ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len) >> { >> int i; >> - const char *ret = p->buffer + p->len; >> + const char *ret = trace_seq_buffer_ptr(p); >> >> for (i = 0; i < buf_len; i++) >> trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]); >