Hi Steven, I guess this email thread was lost on your side. Is my explanation of the "UNTOUCHED_MASK" OK? Should I send you v3 of the patches with the other fixes you asked for? On 3.10.2018 10:34, Yordan Karadzhov wrote:
On 2.10.2018 23:44, Steven Rostedt wrote:On Mon, 1 Oct 2018 16:59:17 +0300 Yordan Karadzhov <ykaradzhov@xxxxxxxxxx> wrote:From: "Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx> The kshark_get_X_easy() functions allow for an easy access to the tep_record's fields. Using these functions can be inefficient if you need access to more than one of the fields of the record. Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx> --- kernel-shark-qt/src/libkshark.c | 185 ++++++++++++++++++++++++++++++++ kernel-shark-qt/src/libkshark.h | 12 +++ 2 files changed, 197 insertions(+) diff --git a/kernel-shark-qt/src/libkshark.c b/kernel-shark-qt/src/libkshark.c index 506511d..a7983eb 100644 --- a/kernel-shark-qt/src/libkshark.c +++ b/kernel-shark-qt/src/libkshark.c @@ -888,6 +888,191 @@ static const char *kshark_get_info(struct tep_handle *pe, return seq.buffer; }+/**+ * @brief This function allows for an easy access to the original value of the + * Process Id as recorded in the tep_record object. The record is read + * from the file only in the case of an entry being touched by a plugin. + * Be aware that using the kshark_get_X_easy functions can be + * inefficient if you need an access to more than one of the data fields + * of the record. + * + * @param entry: Input location for the KernelShark entry. + * + * @returns The original value of the Process Id as recorded in the + * tep_record object on success, otherwise negative error code. + */ +int kshark_get_pid_easy(struct kshark_entry *entry) +{ + struct kshark_context *kshark_ctx = NULL; + struct tep_record *data; + int pid; + + if (!kshark_instance(&kshark_ctx)) + return -EFAULT;Perhaps this should return -ENODEV;+ + if (entry->visible & KS_PLUGIN_UNTOUCHED_MASK) {What's the "UNTOUCHED_MASK" mean?We use the KS_PLUGIN_UNTOUCHED_MASK to check the flag (bit) which indicates if the entry has been touched and potential modified by a plugin callback function. If the bit is set this means untouched. This flag (bit) gets set when we load the data ( libkshark.c / get_records()) entry->visible = 0xFF; ... /* Execute all plugin-provided actions (if any). */ evt_handler = kshark_ctx->event_handlers; while ((evt_handler = kshark_find_event_handler(evt_handler, entry->event_id))) { evt_handler->event_func(kshark_ctx, rec, entry); evt_handler = evt_handler->next; if (!evt_handler) entry->visible &= ~KS_PLUGIN_UNTOUCHED_MASK; }+ pid = entry->pid; + } else {In this case the entry has been touched by a plugin. Because of this we do not trust the value of "entry->pid".+ data = kshark_read_at(kshark_ctx, entry->offset); + pid = tep_data_pid(kshark_ctx->pevent, data); + free_record(data);Would it be possible to do: entry->visible |= KS_PLUGIN_UNTOUCHED_MASK; entry->pid = pid; ? Of course this depends on what that mask means.+ } + + return pid; +} +
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